Buying a PSP. Seriously at the time all my friends were obsessed with Monster Hunter Freedom 2, and demanded I get it. I did, because there were a couple other games (literally two others) that interested me, and I played the game.
What a horrible grindy, storyless, bad combat, bad camera piece of crap that game was. I still just don't get the appeal of that series, and I don't think I want to. The other two games were disappointing as well, but more because I realized the PSP was just an uncomfortable gaming platform, and I'd rather have an Ipod Touch. So I traded it in and never looked back.