I have rather odd tastes in movies, so I enjoy different war movies than most.
Saving Private Ryan - great detail, very good acting and a compelling story. The Missus and I had been married for only a short time when we saw it and sat crying in the theater after it ended and the lights came up. Both of our fathers were in WWII.
Kelly's Heroes - a totally farcical look at WWII, featuring characters that didn't exist at that time (beatniks), but good acting, Telly Savalas, Clint Eastwood, Carroll O' Connor, Donald Sutherland, Harry Dean Stanton, and Don Rickles (!) and some of the scenes ring true although obviously fictional
Slaughterhouse Five - not technically a war movie, but the hero is unstuck in time and that includes his stint as a young chaplain in WWII, it's based on Vonnegut's actual experiences living through the fire bombing of Dresden (and may be the only war movie to ever deal with that)
Patton - great acting, very good action sequences, very close to the truth, but sadly let down by poor detailing as to the vehicles and tanks
Full Metal Jacket - great acting, great action sequences, some of the details lack, some are accurate, it rings true throughout the movie, and as a dyed in the wool Kubrick fan I have to give it the highest recommendation
I haven't seen Das Boot in years and years, and need to see it again.
It disappoints me to this day that there are no movies dealing with the sinking of the USS Indianapolis, no realistic depictions of the Battle of Stalingrad, and no depiction of how Alan Turing and his men deciphered the German Navy code.
_________________
I wake to sleep, and take my waking slow. I feel my fate in what I cannot fear. I learn by going where I have to go. ~Theodore Roethke