After the nuclear holocaust, one man rises from the ashes to become blah blah blah...
http://www.imdb.com/title/tt0105680/?ref_=ttpl_pl_tt

This was a favourite for a long time at our bad movie nights. It seemed to only have a tiny bit of original footage filmed for the movie, the rest coming from like a dozen other terrible movies - and they attempt to weave it all into something resembling a plot - been a while since I've last seen this but I recall aliens, something about exploding stars, undersea mining for unobtanium, the ozone layer, and I think there was a war on mars for some reason all set against the post-nuclear-war-earth thing that so many of these bad movies do.
It's really, really terrible and I'd love for you guys to be subjected to it because I get off on that sort of thing.