What are the best 2d sprite games for the PS2?

I don't know of many, but the newly released Odin Sphere looks superb in that department, and I always thought Guilty Gear XX was up there.

What else? 

Guilty Gear is probably the best sprite based game for ps2,  although Metal Slug deserves a nod too. Odin looks extremely beautiful,  and I can only hope the animation is spot on.