Time has been kind to The Ballad of Cable Hogue, which boasts a 91% Tomatometer rating, and a decent 7.3/10 at IMDB. I didn't like it quite that much, but it's certainly watchable and agreeably quirky.
Cable Hogue is played with irascible and gruff humor by Jason Robards; co-starring as Hildy, the prototypical hooker with the heart of gold is Stella Stevens. (She's really pretty good here, too.) David Warner, Strother Martin, and Slim Pickens also show up.
This is a Sam Peckinpah movie, and it's a change of pace from his more typical shooting gallery movies. He made it in 1970, just after The Wild Bunch. Even though a couple guys are shot, that's more or less a diversion from the broad comedy and love story in the main plot thread.
The DVD contains a lengthy interview with Stella Stevens; not surprisingly, she got along pretty well with everyone except Peckinpah. She mentions that the movie was a total washout at the box office, which explains why I missed it back then.
College courses in economic/political philosophy might want to show the first twenty minutes or so as an example of free-market property rights and capitalism evolving out of a Lockean/Humean state of nature. Just an idea.