[17R3W]

Well also consider what you want to use it for.

If you intend this to be your primary system (that is, this one and only this one, with no current generation home system) and plan to use it mostly at home, (When I got my game boy, I didn't have a NES, or anything else until near the end of SNES life cycle) I would say PSP.

If you want a portable system to use in addition to a home system, as a portable system, then you don't want a PSP. It's to expsenive, it's not designed for use away from a power source for any prolonged time.

The DS can play GBA games so your likley be able to borrow a large selection from friends and pick up used on cheap.

Also, it your looking for a portable media center you don't want the PSP. With only 2 hours of battery life for movies, it's simply not praticle in this regards.