XBLA-Fun multiplayer game(after Braid)

I was thinking about that or either N+.....what's the general opinion on that?AceOfRims

N+ is pretty great, but multiplayer wise Castle Crashers FTW.

Oh, and for other co-op games, Contra and Super Contra kick so much ass.

For competitive I'd suggest MK, or Small Arms (I like it :P)