I kinda liked None but the Brave. I'm a Clint Walker fan though, now that's a man's man. I don't have a favorite really, I lub all the oldies, Operation Burma, Dirty Dozen, Kelly's Heros, The Great Escape (awesome movie).
I think the best from a technical/realism point is Tora Tora Tora. Just incredible looking. I think my favorite scene outta any war movie is in TTT where there are a couple of Zeros flying just over the water, and it gets hit and the way the explosion, engine, and plane falling into the ocean sound are just remarkable.