GET PATAPON!!! It's one of the most unique (and awesome) games of all time!!!

Patapon 1/2
Crisis Core: Final Fantasy VII

And if you don't mind playing downgraded ps2/3 games:

LittleBigPlanet
God of War: Chains of Olympus

uh, sure you don't want a DS instead? got a ton of good RPGs to burn your time away on the road.

RPG's I liked on the PSP (that are not big names)

Brave Story

Crimson Gem Saga

Jeanne D'Arc

Valkrie Profile: Lenneth

Other games I really liked:

Castlevania Dracula X (you can unlock Symphony of the Night as a bonus)

Lumines

God of War

YOU'RE MY HERO!!!

All I play is Final Fantasy Tactics. I'm extremely happy with the PSP but there's nothing else I want or can recommend.

It was in my list first though

Crisis Core: Final Fantasy VII
Jeanne d'Arc
Metal Gear Solid: Portable Ops
God of War: Chains of Olympus
Dissidia: Final Fantasy
Grand Theft Auto: Liberty City Stories
Wipeout Pulse
Ratchet & Clank: Size Matters

Loco Roco 2.

Thanks for all the replies everyone
I was just wondering which psp model was best though
Out of the basic models I would get the 3000 series because its got the most features , But i was wondering if the psp go was worth the money or if I should wait for the psp 4000 next year.