The question is UNDER RATED MOVIES
Ballad Of Cable Hogue...Peckinpah...an unpretentious quite low key movie.
Here is one that is a total SLEEPER...
Disorganized Crime...
https://www.imdb.com/title/tt0097211/?ref_=nm_flmg_act_50
It is a low budget that has an all star cast...with a sharp plot and execution. Funny
Kiss Me Stupid..Billy Wilder..with Ray Walston, Kim Novak and Dean Martin. Wilder never did anything bad.
1, 2, 3... Another Wilder comedy...with Jimmy Cagney.
Billy Wilder was a fkin genius...