I watched a lot of old film noir during the lock down, these were some of the best little known ones (links should open to full movies).
1) Ride the Pink Horse -
https://archive.org/details/1947ridethepinkhorsepersecucionenlanocherobertmontgomery .
Disgruntled war vet travels to rural New Mexico to avenge an old war buddy, and make some scratch by blackmailing the local mob boss. Things go awry when the mobster proves tougher than he seems, and a young senorita falls for him.
2) Crashout -
https://archive.org/details/crashout-1955 .
Six convicts hide in the desert till the coast is clear to make their escape.
Once the coast is clear they roam the southwest, by train, foot, and stolen car hoping to get a piece of some old bank loot one of the convict's has hidden. Along the way they kill police, citizens, hole up with a family they've taken hostage, and double cross each other.
3) Border Incident -
.
A pair of border agents go undercover as a poor migrant and a white overseer looking to stop an illegal worker scam that has been killing off border jumpers, sometimes in very brutal ways.
Suddenly -
.
Frank Sinatra stars as the ring leader of a small group of mobsters paid to kill a very important person coming in by train. To do this they must first find out a way to hide out in a small town for a few hours without being seen by the cops, etc....
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The first 3 are very dark films for their time, and still stand up well today. The first one especially is a very fine bit of desert noir. The Sinatra one is ok, mainly based on his performance, but a fun quick watch at just over an hour.