"Aftermath" was the classic "mad max" style game, with lots of stats and details for patchwork armor, vehicles and a huge variety of weapons. It was a lot of fun and a great system if you like a lot of detail & realism.
Not a game system for post-apocalypse, rather a usable map for such a setting. I very seldom make post-apocalyptic maps, but coincidentally I just created one 2 weeks ago, that I even unofficially named "Mad Max MotoCross" which is a motorcross race track within an enclosed square of broken walls, rubble piles and container boxes surrounding a track of broken road, dirt track through rubble piles, passing through multiple floors of a ruined factory. I figured it was something more interesting than "thunderdome" and more Mad Max in flavor since a chase by vehicles is its theme (of course its for motorcycles and not cars). Also keeping with the Mad Max flavor, 4 towers with turretted ballista to periodically fire at passing motorcycles. I figure the competitors are doing so against their will, as a form of entertainment to crowds serving the owner of the track.
In truth, I probably won't do too many post-apocalyptic maps, this was a one-off, just to scratch a post-apocalyptic itch (which has been scratched and fulfilled, so no need for more scratching).