You know, I really can't think of a game that I truly despised. I remember way back in the SNES era trying to play Earthworm Jim but never being able to get past the first level, but that was cuz I was a kid, and at that time I also couldn't beat Ganon, King K. Rool, Bowser, or any rendition of Sigma, so needless to say my experiences as a child were bittersweet.
I think the only game that I truly dislike, despite giving it every chance, would be Summoner. The game was needlessly dark/bleak, mainly because whoever made the graphics decided to smear everything in shit, including the characters' faces, the story was interesting at first, but after the first half just sort of collapsed in on itself for the age old "You have to find all these bad guys, but we're not giving you any hints as to where they are, and no further dialog or plot to try to move things along. Just check everywhere on this gigantic map that likes to throw you into random battle zones every few steps and maybe you'll find them." Combat was slow, leveling up was a tedious grind that rivaled the levels of some MMOs, and while in the first half your Summoning ability summoned powerful, awesome-looking allies to fight alongside you like in FFX or XII, the second half they all turn into the summons from every other FF, where they show up, do a fancy jig, deal some damage, then take all your MP and leave.