you are crazy though if you think that Ful Metal Jacket isn't one of the greatest war movies of all time....it is one of the greatest movies ever made...
No, I really have to disagree.
The training sequence is terrific, actually. But it goes steadily downhill from there. The scene in the city is brutal... we've got U.S. Marines, who have following orders beaten into their brains so much that they don't even think about it, directly disobeying, and running out like ducks to get shot. It just doesn't make sense. I know they're worried about your buddy, but getting shot only further hurts your unit.
Additionally, the Vietnam sequence lacks a sense of authenticity. The characters aren't easily identified with, and it lacks the connection with the viewer that "Platoon," "SPR," and "Band of Brothers" have. I can't rightly put that movie anywhere near those three. It's not even the best movie about Vietnam ever made, nevermind best ever.