I loved my psp. I really did. But it lacked games then, and it lacked them on the way so I just traded it in for a DS. Since then, they've gotten a pretty good line up of quick, twitchy, arcade oriented games. These days, I am heavy into those so I think it'd fit the bill.
A list of what seems to be worthwhile psp games (some of which I used to have):
Wipeout Pure
Metal Gear Acid
Metal Gear Solid: Portable Ops
Lumines (ported to ps2 called Lumines Plus, but that type of game is better on the go)
Lumines II
Intelligent Qube Mania
Every Extend Extra
Gurumin
Gradius Portable
Ultimate Ghouls N' Ghosts
Virtua Tennis 3
Hot Shots Golf Open Tee
Sid Meier's Pirates!
Metal Slug Anthology
Megaman Maverick Hunter X
Ridge Racers
Loco Roco
Tokobot (ps2 port available)
Exit
Powerstone Collection
Add to the fact you can rip psx games and emulate them almost perfectly, and you have a solid portable.
So yeah, it's not that bad. Seems like a pretty underrated system because of DS' dominance. For 160 it's not bad at all. Not too shabby. Am I missing anything on this list? Thinking of getting a new psp after I get my 360 and HDTV.