Undertale's fandom makes 10x more sense when you realize it started off with the same people from the Homestuck fandom (Toby fox used to do Homestuck stuff before Undertale).

Deep Rock Galactic has a great fandom since everything about the game is about cooperating with others. Risk of Rain's fandom is also pretty chill.

Every fandom that gets popular enough will eventually become kinda toxic and have gatekeepers and people who take the game way too seriously. I wouldn't put too much stock into fanbases unless it's a multiplayer only game.

One of the weirdest must be Final Fantasy XIV community.

On the one hand, they are a bunch of the nicest people you'll find. I've seen several wow refugees coming and getting surprised because there's actual etiquette in dungeons: You don't vote-kick a disconnected player unless 10-15 minutes have passed because they could come back. And people take care of sprouts (newbies), like, really. If there's a dungeon with a new player (a popup says there's a newbie but doesn't say who is it), people give tips about bosses and how to tackle everything. And if there's a plot twist (there's a HUGE ONE in Endwalker's final boss battle), nobody will spoil it.

They have also... Limsa. A city you have to experience to understand. It's weird, but in the cool sense of the word.

But... on the other hand... The hardcore raider subcommunity has to be one of the worst gang of crybabies ever. JFC they whine about everything. Never satisfied, extremely elitist...

Nicest: Factorio. No matter what you build, people will applaud you for it. Someone comes in, excusing their design for neither being efficient nor pretty. "If you had fun building it, it's already great."

Worst: War Thunder. So much toxicity in the chat it's impressive. Plus a fair bit of edgy kids dabbling in racism and neo nazism. I guess that's a side effect of being Free to Play

EDIT: Downvoted by war thunder players.

When I played (before I kicked the addiction), Warframe had the nicest community ever. Everyone was always happy to help out

The Outer Wilds hint community is very nearly an extension of the game. They're very good about providing hints based on what you already know without giving things away, so you still feel good about figuring it out.

Warframe has all three. Late-game players will gladly carry new players through some of the early farms and often foist upon them a crapton of important items that are difficult to get in the early game (we remember and nobody should have to go through the early game alone).

There are some who call the game woke trash and trying to boycot it because the latest female warframe has a larger body type and they can't goon to it, or because of a relationship between two male characters that is hinted at being romantic, or because there are two nonbinary characters (both of whom are far better executed than most in media)... and some who sent the developers death threats for making a particular farm easier for new players.

Nicest has got to be Stardew Valley.

I try to stay away from most fandoms. Any group of people given sufficient time tends to turn sour. I'll say as someone not affiliated with the Undertale fandom, it's a really great story with good combat mechanics and very basic RPG elements. Just my 2 cents.

The helldivers community seems to constantly be one patch away from burning down arrowhead studios, so there's that.

Based on years of experience moderating a public Discord server:

• Weirdest - Trails. Unfortunately, this is weird in the problematic way; think Pragmata. Some of the most well-known names in the fandom are that kind of weird. The series doesn't do itself any favors leaning into it a bit, too. Adding to it is the perception that series fans are gatekeeping when they tell you to play the series in order when in reality, yes, the developers are insane enough to keep building a continuous narrative that's gone 20 years, One Piece-style. Hard to convince people of that when video game series just don't do that.

• Nicest - Stardew Valley. I agree with the others here on that.

• Meanest - Fire Emblem. I've seen some wars, holy hell. Aside from general fandom insularity from out-groups, there are intense, internecine wars going on within the fandom over the newer parasocial elements in the series. And then there are waifu wars on top of that within the part of the fandom that's embraced the parasocial stuff. It's a fandom crucible.

Kerbal Space Program had a super nice community. Well, until KSP2's cancellation, that brought a ton of haters seemingly out of nowhere. Fortunately I think that's blown over and all the kind and creative people are moving over to Kitten Space Agency, which seems like a way better project.

The No Man's Sky people are generally super chill and welcoming! It's really nice.

It's kinda funny, you see the occasional person come in and go "okay but wouldn't it be BETTER if it were combat focused??" (you know, like almost every other game out there). Everyone politely tells them nah, let us have our weird little chill game in peace please, and then they leave. But as long as you're not trying to turn the game into yet another FPS, or going around griefing people, you're cool!

-- Frost

Smash Brothers

Find your local tournament, get accepted by them. They will teach you new tech, be super friendly and accept you as one of their own. Then one of the TO's will sexually harass and/or attempt to rape you. If it's not a TO, it's another member of the community.

Really weird and consistent shit.

Ooh, the weirdest goes to Helldivers 2's fanbase without a doubt. It's so fucking toxic. But I say weird and not mean because they're the friendliest bunch around as long as you don't make your opinion of the game's balance clear. But once you do... the fandom is split into two halves, and they fucking hate each other. So as to not take sides I'll explain each side from the other's view point:

On one side you have the "cry-divers", who complain about literally everything the devs do. They bitch and moan all day long about balance and how the devs' vision for the game isn't the same as theirs. The devs could give them everything they wanted but also include a tiny little nerf, and the only thing you'd hear from them is endless crying about how PvE games should never have nerfs.

On the other side, you have the "glaze-divers". They will defend the devs no matter what they do. Devs just nerfed the weakest gun in the game? Devs just blatantly lied to their community in their patch notes? Devs just shot your dog? Call the glaze divers.

Now obviously its more nuanced than this. But they sure don't know this. It's gotten so bad that someone in the first camp offered the devs an innocent challenge to demonstrate the poor balance of the game. And then someone (multiple people?) in the latter camp doxxed them, and then got them kicked out of the place they volunteer at for safety reasons because they got sent too many death threats. They might have gotten fired from their job too, but I don't remember. It's wild.

The Animal Crossing fandom is all three at once.

Some players are super nice and helpful. They do things like giveaways, share when they have high turnip prices, and let others in their town to recruit moving villagers.

Then you also have people who literally charge entry fees for their island. They'll use this to sell items and villagers to other players. I've even heard of people running scams this way. Even worse is the people who charge real money (this is generally frowned upon in most communities, but pretty lucrative on eBay and Etsy).

Meanest: The Deceit fandom has a high concentration of assholes. The devs have attempted to crack down on the numbers of racists and misogynists with limited success. The fandom is part of the reason half the lobby tends to die in a shootout before the first night arrives.

Weirdest: Snowbreak Containment Zone. The people from China who disagreed with a fictional character cheating on them with another fictional character migrated to this game. Here, the female cast wastes no time in expressing their undying love for the player every chance they get. Regrettably, the Containment Zone could be leaking because the CCP wants to toss the developers in jail for degeneracy.

Nicest: Honestly? The fandoms around small time visual novels. Controversy doesn't really appear, so they're quite nice, if rather vacant.

If you want something similar to old Minecraft, there's Vintage Story which is basically hardcore-hardcore Minecraft. From what I've seen and can tell, the age demographic for that group is about early-20s+ as it has much deeper mechanics than Minecraft does (like accurate temperature and insulation, block gravity and cave-ins, actually physically shaping items into other useful items via forging or knapping, etc.).

I've only played for a bit, but it's awesome. There's a ton of mods for it already too.

Edit: there's also a chisel mechanic in the game so you can shape individual blocks however you want, mix different materials together to create cool patterns and looks, and the edited blocks act like they should; like water and fish will go under if you make a bridge, you can make funky stairs or "slopes" too.

I play old school runescape. the community is either the nicest queer people you've ever met or absolute incels and there really not any in between.

A lot of indie games have amazing communities. Stardew Valley, Kerbal Space Program and Deep Rock Galactic, to name a few. Non-competitive games with active and friendly developers tend to have good fanbases.

On the other hand, a lot of indie games have incredibly toxic and user-hostile communities. Competitive games especially, though you'll also see it when the community becomes upset with the developer (such as 7 Days to Die and pre-redemption No Man's Sky).

And then there are the external factors. A game could become a meme or get covered by a pure cinnamon roll of a streamer and gather a wholesome fanbase despite its content (Doom 2016 comes to mind), or an existing friendly community could get overshadowed by a bunch of 4chan rejects if the wrong YouTuber covers the game (see any semi-obscure game reviewed by SsethTzeentach - I'm still upset about Starsector).

My Summer Car has weird fans, but you need to be weird to enjoy that game.

The Satisfactory community is very encouraging and helpful.

Nicest: TES. I've met some of the nicest people and some of my best friends in the TES community, especially back in my ESO days when I ran a large guild.

Meanest / Most toxic: Planetside 2. I considered Destiny 2 for this but Planetside 2's community takes the cake. It's an old game by this point and the only people left playing it are the seasoned, cranky vets that have been playing for thousands of hours and hate everything and have zero patience for anyone who dares try to learn the game. Death threats, harassment, stalking, TKing, etc is all a frequent occurrence. There used to be entire outfits (guilds/clans) of players that were dedicated to playing as dirty as possible or otherwise being huge assholes.

Unfortunately I play Rocket League... this game is ridden with bad actors. I keep the text chat on because when you encounter good faith players it's the nicest thing to be able to converse, but the price is really high. Almost constant abuse, under all its forms : racism, insults, etc. I think it's mostly unattended teenagers, but boy do they ruin stuff.

Those of us left playing Titanfall 2 are generally a pretty great bunch. Most of the people who still play actually engage with the movement system and my word, that game has aged well. I love the community; it's small enough to recognize people, but large enough to maintain an active base at all times of day. As for the meanest, definitely Rust. That community is such a cesspool. It's not even funny. Nowhere else will you find such a wretched hive of bigotry and ideological subservience. Weirdest to my mind is probably the Batman Arkham one. From what I understand they have splintered, with one side developing an internally perpetuating sort of humor that focuses on making no sense, or being intentionally absurd in some way. The other side has remained largely a normal game community, but harbor an intense hatred for the splinter cell fandom insanity.

From what I've seen, The Stardew Valley crew is just chill and helpful.

I'd rather not name it, but the worst experience I've had came from a community small enough that everyone knew everyone. I've been in plenty of communities like that, many of them can be the nicest, but some can turn quite cliquey. One of my favorite games of all time is one I can no longer play because someone with power and influence in that clique used their influence to bully me out of the competitive scene.

Weirdest: Five Nights at Freddy's, Sonic the Hedgehog,

Nicest: Super Mecha Champions (when it was still up, but it was shut down on PC sadly), Goddess of Victory NIKKE

Meanest: Dead By Daylight (playing as Killer and trying to win or even worse actually winning will result in all but guaranteed death threats in end game chat from Survivor players), Undertale, Pokemon (actually basically anything Neu-Nintendo), League of Legends

I haven't delved deep in fandoms of most games, but Final Fantasy XIV has a very nice community.

Hades fandom was always pretty cool from what I recall, at least in my own experience

I have at this point roughly 1.6k hours in a bunch of Monster Hunter games, though by and large the vast majority of them are in Generations and Generations Ultimate. I've never liked concerning myself with meta builds, certainly not in a cooperative PvE game that I regularly would play solo.

Now I'll preface this by saying I've made some lifelong friends in the community, one of which I traveled halfway across the US to visit a few years ago. I don't think the community is all bad, but I've found so many people who will do very little other than try to minmax DPS build via the current meta and shame others for not doing the same.

One not so bad instance I had was when I was trying to break into some higher tier armors. I was going into a fight that I figured would take a long time, knew was going to deal a decent bit of burst damage, could easily knock someone out after that burst was dealt, and most importantly had 3 people joining. Because of these factors, I went with a build where I would primarily support everyone else, then try to keep myself alive, then any time in between those priorities I would try to deal some damage. A large portion of my armor was kitted out to increase the effectiveness of my items, have them affect my teammates, make my items have chances to be reused, then I set up my inventory so I was carrying a lot of healing items and could craft more when necessary.

One of the players in that 4 man squad I remember specifically trying to shame me for bringing a lower damage weapon (chosen because it had more skill slots), having significantly lower armor rating than the others (because I only had mid game support armor, not late game), and for not dealing much damage (because I was trying to keep him and the others alive). I say this one wasn't too bad because I also remember specifically that others in that very party pointing out that although I may not have had much armor it didn't matter much since I didn't engage much and they had noticed how much I was keeping them alive which would have otherwise failed us all the mission.

The worse situation I remember was getting sent DMs about how my build was bad, I was using awful skills, I had one particular armor set that was "a trap for new players", and to "please just use [x] armor set". They didn't like I was using three skills each decided upon because they would fix reasons I kept getting combos interrupted then killed and told me none of them were necessary because "if you're in the right spots then you won't need any of those",aka "git gud". I could somewhat understand this mentality if we were in a PvP competitive setting, or if we were in a group together actively working to speedrun this monster, or if I had asked for feedback on my armor. This entire discussion came about because I was trying to share with the wider community: "hey I just found about this neat skill exclusive to this armor set!"

Linux?

The cruelty squad fandom was insane with people dressing up in business suits for lets plays to get in that CEO mindset.

Also I find it amusing that most of the fear & hunger fandom is queer & horny.