Stalag 17, about US Airmen in a German POW camp, is a good-enough story ruined by tedious repetitive jokes, mostly about Betty Grable. William Holden does a good job as the camp’s black-market-operating cynic. Otto Preminger is the iconic German camp commandant. It’s not the actors’ fault, the humor is just moronic. And I say that as someone who likes The Three Stooges.
Some sources online say Hogan’s Heroes was so similar to Stalag 17 that there was a lawsuit about it. If so, the TV series did it right. Skip Stalag 17 and watch a few episodes of Hogan’s Heroes instead.