There's a lot of good arguments out there. Pong for being the "first", Pac-Man for making arcades insane and bringing in big money, Tetris for its wide appeal, Mario 64 for convincing everyone 3d games work, Doom for popularizing the fps, Wii Sports for its ubiquity, Farmville for starting what would become mobile games (which as much as gamers hate to admit, they make more money than every other platform combined). It'd take a pretty convincing argument for me to fully believe any of them but of mine I'd make an argument for Pac-Man, but my heart wants it to be Tetris

personally I think its Doom

Rogue. You've heard of Roguelikes? It influenced more than just them. Probably every action RPG owes it something.

Oblivion: introduced predatory micro transactions

Doom.

People are still making Doom WADs. And have you ever heard of the FPS genre?

Half-life. Maybe it didn't innovate specifically anything, but it's the first real maturely designed game, with incredible attention to detail and focused on conveying a cinematic story in fully interactive environments.

And don't get me started on HL2.

Don't we have enough wars already?

I think naming a single game is hard, but most influencial franchise in gaming would have to be Mario. Between the platformers, smash, kart and the music it is just so widely recognizable.

I genuinely think FarmVille is a contender, as I said in the other thread, but realistically gaming has existed long enough that picking just one is kind of impossible. There have been several shifts and revolutions. With how much of the revenue in gaming currently flows through mobile games, gacha games and live service games etc I really do believe FarmVille might be the strongest influence on the current landscape of gaming. But historically, it's possible Doom was more important for its development. Or even Super Mario Bros for putting home consoles on the map. I could even see an argument for Minecraft - it's completely ubiquitous and an absolutely global phenomenon.

Gaming is already big enough and has existed long enough that the question is fairly unanswerable. It's like picking the most influential movie. Is it Birth of a Nation for inventing cinematic language? The Jazz Singer for popularising "talkies"? Is it Workers Leaving the Lumière Factory in Lyon for being the "first"? Is it The Wizard of Oz? Is it just Citizen Kane? The truth is, it's none of them. It's all of them.

Ultima. Easy.

Tetris

Probably Mario

Especially if we consider "influence" beyond influencing other games.

Minecraft might be a good contender in terms of spawning the survival genre and also having so many mods used to pioneer entirely new game modes and even having a major part in machinima and Let's Plays and such things on Youtube.

Mario Bros.

Literally every gamer has played it or a game like it. Even non gamers recognise it. It's copied and iterated on to this day.

It certainly wasn't the first 2D platformer, but it's success made everyone else go "that's what we're making now"

Like I said in the other thread, I vote pokemon. I don't think you can go too much older, because the audience was just so small relative to more modern games. Scale is a major factor to influence.

Many other games have "defined" their genres, but few have done so quite as completely as Doom (1993). And on top of birthing the entire FPS genre, the practice of making Doom run on any electronic device with a screen and a CPU has long been a fantastic exercise in programming and hacking. The possibility of implementing Doom in everything from calculators to pregnancy tests to Captcha in a browser window has kept the game in the public consciousness for decades, and will continue to do so for decades to come.

Of course the real answer is Clash of Clans, because it popularized mobile gaming and skyrocketed that platform's revenue to the point that it outpaces every other gaming platform combined, but I'll boycott BAFTA if something riddled with microtransactions gets any recognition

I can't see Space Invaders so I'll say that. It was a tour de force when it first came out, raking 13 billion dollars in today's money (citation needed).

FIFA, for pioneering the idea you can release the same game every year with minor cosmetic tweaks.

Robot Odyssey.

Not one mention of WoW anywhere in this article or this thread, I find that at least somewhat surprising!

What did you put in? I wrote an essay on how inevitable praise of Dark Souls also applies to Metroid but then deleted it as too pretentious even for BAFTA.