Unfortunately a thread of this type will exhaust all of the movies that are actually good within a few posts, so since it was not mentioned I thought I would throw in an awful one, In Enemy Hands
http://www.imdb.com/title/tt0316824/
Plot: At the height of Hitler's infamous U-boat war, the crew of the U.S.S. Swordfish were heading home after months at sea. They never made it. Now prisoners of war aboard U-boat 429, a small group of American survivors will find their loyalties put to the ultimate test when they're forced to join their German captors to fight for their very lives.
Yes, it is as bad as the plot sounds.