Star Wars Vs. Fellowship of the Ring - Pretty close, a tie or Star Wars by a hair.
Empire Strikes Back vs Two Towers - Empire is so much better it's like comparing Unforgiven to Paint Your Wagon. Two Towers doesn't even warrent comparison to a masterpice like The Empire Strikes Back. The victory is, in the words of Darth Vader, "All too easy". Sure the EE gains a little ground back, but it's a laughable comparison.
Return of the Jedi vs Return of the King - Haven't seen RotK so I can't really say, but from what I've read I'm thinking of waiting until the EE comes out so I don't repeat my theatrical release TT experience. Unlike a lot of folks, I loved Jedi. The lightsaber fight between Vader and Luke in the end sends chills up and down my spine. The scenes with Vader, Palpatine, & Luke are great. Incredible starship combat sequence, and the flying through the death star part was great. Sure the Ewoks were a little silly but they didn't detract one bit for me.