First, a couple of disclaimers: I've only seen the original 1957 version (so I don't know how the new one stacks up) and I could only find the remake's trailer on line - but The 3:10 to Yuma would make a great game
It's a bit psychological, so it'd require some reworking from the GM, but the TL;DNR version is: an outlaw was captured, but word got back to his gang. The Hero has to get the Bandit on the 3:10 train to Yuma before the Bandit's men gun him down.
So, outnumbered, the players have to get Their Bounty to the proper authorities while under the gun of the Bandit Gang's nose.