should I buy?....

my bday was on the 23rd and I got some cash. I was gonna pay bills and what not, but I decided that since it's bday money i'm just gonna waste it and like it. I think I'm in the mood for a new video game but don't know which one I want. I just got Sword of Mana for GBA and it rocks, but I can't play GBA full time since my roommates fight me for it and the screen is so friggin small. So, out of PC, GBA and PS2, which game would you guys suggest for one of these systems?