Phantome Menace sucked and it was barely held up by the stunning performance of Ray Park as Darth Maul. Attack of the Clones had a good premise, yet all the lovey-doveyness spoiled it. (I liked Mace's "This party's over"). Revenge of the Sith was a purely amazing, lighstaber duel-enriched firefight that was thrilling from beginning to...well...up to that end scene on tatooine (too cheesy). A New Hope was nice and sentimental, but not THAT good, though it had some excellent lines in it:
"...Us, two droids, and NO QUESTIONS ASKED"
-Obi-Wan
Empire Strikes Back was the best but barely edged out ROTS. It had everything: a snowy ground battle with giant walkers, Yoda teaching Luke, Cloud City with Vader (less lame than the first one) and Han getting frozen, all in time for an epic lightsaber duel. In comparison, ROTJ was not as good, and a bit worse than ROTS, but a green saber was cool, Palpatine was awesome and Leia was HOT!
Overall, though, Empire Stirkes Back was the best.