You have probably seen some of these. If not, you should check them out. I put stars (*) next to the most recommendable ones.
War movies, most of which are from the Vietnam war:
-* Apocalypse Now (This one is creepy, but really good. Marlon Brando kicks ass!)
- Full Metal Jacket (The drill scenes are hilarious, the rest of the movie is serious)
- * Platoon (DO IT!! Best war movie ever)
- Saving Private Ryan (Not my favourite, but it is quite enjoyable. And the effects are pretty darn good)
- * Schindlers List (A serious movie about the german holocaust. A must-see)
- Das Boot (A german movie about a submarine crew. Not very much action, but you can really feel the emotions of the crew)
- Der Untergang (The last days of Adolf Riddler)
Others:
- * Forrest Gump (A true classic. So many quoteable moments)
- * One Flew Over the Cuckoo's Nest (Jack Nicholson plays a loonatic. One of those movies that make you think about it afterwards.)
- * The Godfather (Do I need to say more? It's an offer you can't refuse. Number II and III are also pretty good.)
- * A Clockwork Orange (A complete mindforget involving rape scenes and "ultra-violence". You're either gonna love it or hate it)
- Lord of the Rings - Fellowship of the Ring (A tad long, but very epic.)
- American History X (A movie about neo-national socialistsm and racism.)
- Amadeus (A movie about Mozart. Somewhat enjoyable even if you're not a fan of the music, but a masterpiece if you do.)
- Slumdog Millionaire (It looks like one of those bollywood chickflicks, but it isn't (not entirely). It's a movie about the life of a poor kid from India)
- Monty Python - The Holy Grail / Life of Brian (Monty Python will always make you laugh.)
- The Thing (An 80's horror/thriller movie. It got a special vibe to it, even if the effects are old. Very psycological)