bahahahah that's such a hard question, I don't know if I truly hate any of them
on top of my head I don't like the gen 5 dog, the gen 5 monkeys, and I found the gen 8 legendaries boring as hell
special mention to smash bros pikachu, not coz i hate pikachu but because i'm tired of the "he's the best character in the game" propaganda that's never been true