My buddy and I are looking at holding a classic games tournament in the coming weeks, and we want it to span a few systems. Of the systems available, we've got:

Atari 2600
Colecovision
NES
Master System
Turbografx-16
Genesis/Sega CD/32X
SNES
Saturn
Playstation
N64


I'm looking for games that are either directly competitive or something score-based. They don't need to be multiplayer. We want to hit probably four systems, but we're not sure which yet, so suggest anything. It will probably be standard brackets with maybe 16 people.