Well, I'm a huge Pokemon fan so I would choose Pokemon Heart Gold hands down. In fact, I would choose that over any Zelda game that could be offered. Even Zelda Wii. It just has so much more content then any other game, for starters. And, with excellent and fun Wi-Fi options, and the endless competitive battling scene. I don't believe that I would get bored of it very fast. Or ever. So yeah, definitely Pokemon Heart Gold.. Can't wait till Sunday.
Oh, and Ver-go. I haven't play FFXIII first hand, but I heard that it's just different. Not bad. And a big FF fan like you that bought a PS3 basically to play FFXIII should probably get it.