What makes a "Memorial Day" movie different from a "Veteran's Day" movie?
Given the first honors those who died in service and the second honors all those who served, alive or deceased, I think I have to go with "Saving Private Ryan" for Memorial Day, followed by Platoon and Tora! Tora! Tora!. Not much in the way of great Korean War movies out there (I don't count M*A*S*H as a "war" movie), but Bridges at Toko-Ri and Pork Chop Hill will do, with the latter being especially grim.