Lots of good ones listed already, but a couple I always watch when on TV are "The Train" with Burt Lancaster causing the art-stealing Nazis all kinds of grief, and "Paths of Glory" with Kirk Douglas defending three soldiers charged with cowardice in WWI.
Can't remember the name of it right now but someone will, its a bunch of jewish soldiers set out to kill hitler and one carried a bowie knife and scalped the germans and another carried a baseball bat to crack some skulls..... great movie