FFX.
Dunno how old i was when i bought it, but i remember reading some reviews in magazines (wished i had discovered the internet sooner) and being dazzled by all the praise it got. What followed was over 9000 hours of annoying dipshits playing volley-ball and tedious fucking boss-fights (what? don't tell me that you didn't know that potion X kills Monster Y?) and boring ass puzzles. The only good points i could give FFX is that Bahamut looks bad-ass, but thats it.
From the moment i finished the game, i knew to stay away from most JRPGs, that is excluding Demons Soul, i consider RPGs in the context of not where they are from, but what kind of game it is (heavy anime/manga art-styles etc.).