Here's a quick list of cult films that don't get mentioned when it comes to dealing out some inspiration for a post apocalyptic campaign. Anyone of these films makes great fodder for a wasteland of weirdness. These are especially great for Mutant Future or any old school post apocalyptic adventure.
A Boy And His Dog From 1975 hardly ever gets spoken about today but there's some good bits to mine from this old school classic. Take a look.
Ahh the classic Death Race 2000 from the twistedly classic mind of Roger Corman doesn't get mentioned to often but it remains an old favorite of mine.
Let's see there's also the other classic that often gets a mention but hardly looked at. The classic Roller Ball!
The Ralph Bakshi classic Wizards hits all of the high marks for crossing the classic fantasy elements right into post apocalyptic genre with no regrets. A simply great film to pull from!
Here's a lovely little gem that hardly ever gets mentioned when it comes to post apocalyptic movies! Screamers was a weird little movie that crossed the line from science fiction horror to high weirdness out in the wasteland. This one from 1995 isn't thought of at all by most folks and is easily adapted into a really nasty little piece of work for a full campaign.