I broke my vow and decided to get a Sony product, so I got a PSP in the mail, 3000.
So I was going to go to GameStop later this week and stock up on games, any suggistions?
I love music games, the PSP comes with Rock Band, and I plan on buying Parappa and Gitaroo Man.
Any other big PSP games?

Patapon 2 is a rhythm based game

God of War Chain of Olympus, best game for the psp. Buy games in amazon or ebay, way cheaper than Game stop. Especially if the games are old. (old, not used)

Patapon 1 + 2 could be up your alley since they are rhythm based. And I'm taking a guess that you like earthbound from your avatar, so you probably will want to look in on psps selection of jrpgs, of which it has a lot.

Rock Band is the best rhythm game, but I think the PSP only comes with a demo of it, not the full game. Patapon is a good rhythm/strategy, but only if you like difficult games.

As for other genres, Crisis Core, Final Fantasy Tactics, Dissidia, Jeanne d'Arc, Hlaf-Minute Hero and Chinatown Wars

Heres a starter list:

Fighting
Tekken
Mortal Kombat
Soul Calibur
I think there is a port of street fighter alpha
Blazblue in a few months

Action:
Killzone liberation
Chains of Olympus
Prinny: can I really be the hero?
Jak and Daxter
Ratchet and Clank
Monster hunter
MGS Portable ops

Racing:
Wipeout
Motorstorm
Gran turismo

RPG
Crisis Core
Disgaea
A bunch more that I cant think of

Thats a solid start, but you should do some research to find the games best for you

He probably got the special edition which came with the full game.

Back when I had a PSP my favorite games were Megaman Maverick hunter X, Daxter, and Ape Escape. Also you just have to get LBP

Jeanne De Arc, Syphon Filter (either of them), Resistance Retribution, Daxter, Loco Roco (amazing demo!). That's enough to start with.

Buy some comics, too.

Monster hunter unite,amored core, and Little big palnet psp.

GOD OF WAR, PATAPON 2, KILLZONE:LIBERATION, DAXTER, BEATS, STREET FIGHTER ALPHA MAX 3....