I am SO going to get flamed for this post.
Deus Ex - it bores me to death. I kinda think it's awesome in concept, but still...
Planescape Torment - Getting out of the first place was boring enough, but trying to get out of the Hive...I'm sorry, I just don't feel it. Maybe it's something with it being a top-down rpg. Baldur's Gate is one of the few of those I've enjoyed.
Bioshock - It's not bad per se, but I think it'd be better as...either a (mini)series, movie or book.
Super Mario Bros. 3 - It's not BAD, just very very overrated.
Earthworm jim - Do I need to explain?
24 - if that counts, I suppose
Half-life 1& - again, not as much bad as overrated. I repeat, they are not bad games, simply overrated and hardly as innovative as people claim.
A good chunk of the mega-man series - repetitive platformers that never changes formula - ok, never is maybe exaggerating.
Pokemon - again, not sure if it's "cult" but it's definitely overrated.
The sonic games - Hold right, occasionally push the jump button, then win.
Honorable mention: If fallout 1 and 2 are anything like planescape torment, I'd rather play through Duke Nukem: Manhattan Project with my hands submerged in ice cold water while listening to J-pop.