Both have an amazing cast. FMJ obviously doesn't have nearly the star power as AN, but you feel connected to the characters all the same. Directors are about even, I'd give a slight advantage to AN because Coppola nearly went crazy during the filming and the amount of insane challenges in finishing the movie.
Both have KILLER soundtracks. You cant go wrong with the freaky music in AN which was recorded in part by Mickey Hart of the Grateful Dead & the Diga Rhythm Band doing the Rhythm Devils... plus there's Suzy Q and the Stones' Satisfaction... and THE END by the Doors makes a defining appearance. But the pop songs in FMJ are just crazy, Wooly Bully, Surfin Bird, These Boots are Made For Walkin are all turned inside out and you can't hear any of those songs without thinking of that flick.
As far as the story, I have to agree with Cajundude that AN is just incredible because its background as the Conrad novel is really key. The story is one part madness and one part murder, but the other things that happen (Duvall's character, the guys on the PBR) are all important in setting the tone. By comparison, FMJ is almost comedy because no matter how you slice it, the entire first third of the movie with private Pyle is manic and awesome. You almost feel sorry for him.
There is no question that each of these movies is among my top 5 of all time, and both of them are phenomenal. In my opinion, no war movie has ever come close to these two in many, many years. Movies like Hurt Locker, Black Hawk Down, and Saving Private Ryan aren't even in the same league as FMJ and Apocalypse. They aren't even on the same planet in terms of impact and intensity. Maybe they are more bloody or "exciting" in terms of action (and that's a big "maybe") but they are video-game versions of war movies compared to those two.
But I will have to say that, if given an entire night off and a desire to watch a classic war movie, and really get into it, I'd have to go with Apocalypse Now. There are 3 reasons:
- Robert Duvall's character, even after watching this movie so many times I couldn't even count, never gets old and is always entertaining as hell
- Brando is a freaking icon. I honestly think that kind of role - some central character of evil - is what is missing from FMJ to make it a better movie between the two
- And last but not least - Dennis Hopper is THE MAN