Star Wars. I saw maybe 20 minutes of one film of the original trilogy, and 10 minutes of one film of the second trilogy, none of the rest. It's beyond me.

I technically only played my first pokemon game (official) on emulator around 2020, despite my brother having gen 1, so I wouldn't feel too bad about that personally.

Anyways, some people would probably look at me weird for never having played games like any Resident Evil games or any of the Mass Effect games or really many games like them (BioShock series not included, love those games). Same thing for anything Final Fantasy (excluding 10 on PS2, which I never finished and lost the memory card with my save file). Name just about any game over the past decade that won awards at a big game show and there's a real good chance I've never played them once. Never played on a Wii U (a blessing), Xbox past 360, or anything past PS3.

I have also never seen most of the marvel Rickey Rats owned films. Same with a lot of live action films. Name a real popular one to come out over the past decade, maybe decade and a half, and I probably have not seen it (Sonic not included because I actually enjoyed the first couple and cannot wait to eventually see the third despite the VA of Shadow). Hell, even growing up I didn't watch many live action films because I just didn't care compared to the amazing world of animated cartoons, so my knowledge of live action films is a lot lower than my cartoon knowledge.

Speaking of cartoons/animation, I have never watched a single episode of Demon Slayer, Jujutsu Kaisen, Kono Suba, or JoJo, among an absolutely massive list of anime that currently have relevance and such that are currently popular and in people's minds. Also never seen influential older stuff like YuYu Hakusho or Fist of the North Star either.

Every single answer on this thread so far, except for titanic.

Everything other than squid game, among us and minecraft

I know it's been out forever and a day, but Prometheus being in the Alien canon is kind of a spoiler.

Never watched Game of Thrones or Stranger Things. (Or countless other shows)

I've never seen 2001: Space Odyssey, I already tried watching it multiple times, but always end up falling asleep.

Similarly, I've never managed to finish Firefly, usually watch a couple of episodes and forget about it.

Also up until very recently (less than 2 years ago) I had never played any Call of Duty games.

I have bookshelves full of Superman comics, graphic novels, books, basically anything in print I can get my hands on. And I've read every last one of them. I grew up on Christopher Reeve Superman films and will still watch all 4 of them. I've watched the old Fleischer cartoons, Super Friends, the 90s animated series, and all Justice League shows. I own the entire Smallville series on DVD. I was one of the dozen or so people who subscribed to DC streaming service before Max. And I've watched every Superman movie and TV show that came out in the last 25 years.

I've never gone back and watched Lois & Clark: The New Adventures of Superman. There is no reason I've never watched it other than I just haven't gotten around to it.

I can’t make it more than an hour though the first Lord Of The Rings without falling asleep. It just doesn’t fancy me.

Not quite what you are asking, but the first time I saw the video from 9-11 of a plane crashing into a building was around 2014-2015 when I moved to NYC. The people I was working with there couldn't seem to believe that I had never seen it.

I haven't watched a lot of movies in general, be it mainstream or indie. Completely my own fault, since I'm built different when it comes to setting up a roadblock for myself, in that regard.