There's Symphony of the Night available on XBLA and (I think) PSN for like $10.
Also Shadow Complex for XBLA (I don't know what it costs though). It's a 2d Metroidvania style title made with the unreal engine.
Castlevania Dawn of Sorrow, Portrait of Ruin and (my personal fave) Order of Ecclesia for the DS following the same Castlevania + RPG elements of SotN.
There's also Castlevania Lords of Shadow, which IMO is fairly good but diverts from the typical Metroidvania style and goes with a God of War style hack and slash aesthetic. The static camera is a little annoying for me, but it was still enjoyable.
Other than that there's only Metroid: Zero Mission and Metroid Fusion for the GBA. If you have an older DS with a GBA slot they're still great games. I'd stay away from Metroid Prime: Hunters though... it's primarily a multiplayer FPS.
Other than those there's really only Super Metroid on the Virtual Console (Wii). in my opinion it's the best game ever made, so I'm kind of biased on that one
EDIT: damn ninjas!