I for myself always hated beating Gades in Lufia II in the 1st encounter to gather his sword, for it always took me hours and hours to level up just enough to not be wiped out instantly.
Always cursed my greed for his blade ...
besides that, black Summons in Final Fantasy X also cost me some sweat, especially Bahamut and those three bug type Summons ... I also do not like being forced to look up guides and that's what was necessary to come up with a halfway helpful tactic ...
EDIT: I totally forgot: Chocobo race with balloons and birds in Final Fantasy X ... If you're a kind guy and want to test your anger management to the fullest, just try to reach the goal at 00:00 ... it brought out so much hatered in me, that I was scared of myself!!