I'm a big fan of the original Mad Max from 1979. What later became solely post-apocalyptic is at first a hard-boiled, dystopian detective flick with elements of cowboy movies. Plus, that ultra poser-fied '59 Chevy the bikers take to pieces was so cool to me.
Speaking of cowboy movies, Dead Man starring Johnny Depp is a dead-wringer for one of my favorites. I've watched the 'Dollars' trilogy, but Dead Man is in a league of its own.
It's this black-and-white piece of psychedelia with a soundtrack by Neil Young, telling the story of an accountant on the run from bounty-hunters after a freak accident in a frontier town. He's aided by a lone Canadian native who calls himself 'Nobody', and comes across various odd characters- missionaries, schizophrenic outlaws, and finally the Makah indian tribe in Neah Bay. Chasing after them are three bounty-hunters, and we see them bicker with one another in various 'meanwhile' scenes.
All in all, an odd experience that's not for all- it can be kinda pretentious- but I certainly enjoyed it!