For games that are in genres that I'd actually play:
Final Fantasy 6 (3): I grew up with the NES, and when we got a SNES I got whatever games I could from the $20 bin at Toys R Us. I had some friends who were a bit better off that loaned me some games, and I eventually managed to get my hands on a copy of Chrono Trigger (as well as other RPGs like Breath of Fire), but when I borrowed FFIII from one of them I was just... underwhelmed. I didn't really care for the characters, it felt pretty slow initially, and I remember getting to a bit with a bunch of moogles in the party and I just put it down and never went back.
I've since tried to play it a few times here and there, but it never really manages to hook me... but people sing the praises of it high and low and I just don't really get it because I can't get over the hump.
The Witcher 1/2/3: I just really don't like the combat, honestly. I've tried playing all three, and managed to get enough time into them to appreciate the good bits (voice acting, story, quest lines) but the main meat and potatoes for me in a game are exploration and combat, and only one of those really works for me in those games. I had a better time in the first game, all things considered, because I guess I was willing to allow a bit of jankiness from an older game, but I bounced off Witcher 2 pretty quickly combat-wise, and didn't manage to get more than many 1/3 to 1/2 way through Witcher 3 before I just admitted that I wasn't having fun.
Persona 3: I got into the games with P4G on my Vita, so part of this is 'going backwards is hard' in terms of QoL improvements and what not. But I also played the PSP port of Persona 2 (whichever one was actually ported in English) and had a good time (not so much with the PS1 version of the one that didn't get the English PSP port... that one was rough) so I guess its just the game didn't resonate with me as much as the other ones did... Maybe it was the characters or maybe it was the cuts that were made for the P3P version of the game, but it just didn't hit the same.
Otherwise, a lot of military-style FPS games (stuff like Halo or Destiny or Timesplitters or even Goldeneye 64 are/were fun), the more recent sports titles (up to the Dreamcast/PS2 I was fine with them, but more realism doesn't do anything for me), and stuff like MOBA or visual novels or 'walking sims' or battle royale or whatever those asynchronous horror games just don't tick the boxes for me in terms of what I want from a video game.