I'm gonna over some more obsure tiles... 

Panzer Dragoon Orta...an on rails shooter, but don't let that fool you. You 'llbe too busy shooting at stuff to worry about  "freedom" anyways :) A unique story and artstyle, incredible music, pitch perfect controls and graphics that STILL impress. If Halo and Halo 2 are the top two Xbox games, Panzer Dragoon Orta is without doubt the third.

Crimsion Skies: High Road to Revenge...an excellent, Rouge Squadron like shooter with great style, sound and graphics. Easily found in many stores for a cheap price.

Conkers: Live and Reloaded: The multiplayer is completely redone from the N64 version, as well as the graphics. The graphics will melt your eyes out, and the game's self referential humour never fails to charm.

It is a light-hearted fighting game (nicer way of saying shallow), but that's why it works so well. Anyone can jump in and have a good time, and advanced players can employ those crazy techniques like wavedashing and short hops. It isn't deeper than SC/Tekken/VF, but it's a great fighter on a system lacking them.

I bought one three weeks ago:

 Advantages:

Cheap

Cheap Games

Many Games

Disadvantages:

Will die out soon

Older games=Harder to Find