I would say LOTR, I love Star Wars so much and A New Hope (Original Part One) and Empire Strikes Back (Especially) are downright awesome -- they kinda did so much for our culture. It was more than just a movie and hell it's years old yet there are lots of fan clubs and conventions still based on it. Sadly, Star Wars got weakened right around the time Return of the Jedi came out; and don't get me started with Phantom Menance and Attack of the Clones ... absolutely horrible.

As for LOTR; all three movies were great in their own rights -- Fellowship did an admirable job building up the plot while Two Towers gave us a darker, grimmer look. And Return of the King goes into far detail at the end explaining what happens to the hobbits. And well the battle scenes are downright incredible as is the soundtrack.