1) Episode V - The Empire Strikes Back (1980)
2) Episode IV - A New Hope (1977)
3) Episode VI - Return of the Jedi (1983)
4) Episode III - Revenge of the Sith (2005)
5) Episode II - Attack of the Clones (2002)
6) Episode I - The Phantom Menace (1999)

I really wanted to put Episode 1 over 2, but the overuse of comedic humor, especially with Jar-Jar was too much.