Nothingness: Ground breaking? What about a machine gun wielding number 1? dAGGER would like this too as it could all be over in a couple of moves :)

My vote is for atomic espionage, extinction espionage, the canon piece, the 3 game match and the 4 player individual (in order of ease of implementation).

Good post Mark!
I would also add a 10x8 board variant (10 is the width and 8 is the depth).