I remember grindin a lot on Grandia before the final boss but I still couldn't beat him and I was so bored of the battle.
Also, Chrono Cross, I was at the final dungeon, i remember I had to kill some color guardians but I couldn't so i put off the game for a couple of months, when I returned I discovered my save file was GONE!
And the more recent dificult game I rage quit was Resonance of Fate, In another stage of my life I would still play that game, but now I don't have much time, and really don't want to spend that little time losing and dying :/
3DS FC : 4339 - 3326 - 7693. Add me :) Nickname Tin