I totally looked over this post earlier.

Bleach DS gets a thumb-up from me, while you're at it get Osu Tatakae Ouendan as well (since both are imports). Then get Elite Beat Agents next week.

Castlevania Dawn of Sorrow is probably the best all-around action/adventure on the system right now. Mega Man ZX is cool, and New Super Mario is classic. I'm gonna pick up 'Mario vs Donkey Kong: march of the minis' today if my slow store doesn't have FFXII.