Three Cheers For Master. Struggles a little with the small footprint aspect, board states can get pretty large, but it is small and portable, quick to play, and a LOT of fun.

I often refer to it as the good version of Munchkin, in that its very funny, and features a lot of direct attack mechanics. The key difference is that every attack relies on exploiting a weakness in the opponent's board state. Instead of just feeling like you got fucked, you're always left thinking "Shit, I should have seen that coming. I'll do better next time."

Also, the card art and flavour text are some of the best I've ever seen.