I'd say VII, because that's the big one. Everyone plays it at some point.
But yeah. I'm a big KH fan. Roxas is and always will be my favorite. Playing Days in Japanese made me love him more. xD Hahahahaha, he's a pottymouth in that game. Can't wait for Birth By Sleep. Still debating whether or not to buy the Japanese version since its release date is coming up...
Dervis said:Kingdom Hearts was what re-ignited my love of Disney! I've played both 1 and 2, and am anxiously awaiting Birth By Sleep. I'm also a huge fan of FF, so this game is like the love child of my 2 favorite franchises!