For me it's definitely ROJ. It was the movie that was in cinemas when I first started to get aware of Star Wars. It had the coolest Space Battle of the classic trilogy and the final confrontation between Luke, Vader and the Emperor was just epic.
So it would be:
1. Return of the Jedi
2. A New Hope
3. The Empire strikes back
4. Revenge of the Sith
5. Attack of the Clones
6 Phantom Menace.
Revenge is the only one of the new trilogy that I really like. Clones is so-so and I practivally hate Phantome Menace. Without Qui-Gon, Obi Wan and Darth Maul this would have been one of the most lame movies ever. Even with those three it never feels like a real Star Wars movie at all.
1. Attack of the Clones (actually enjoyed this one a lot compared to most people; I'm surprised).
2. A New Hope (it's the damn sunset...)
3. Revenge of the Sith (I can't really describe why; maybe because it's the most action-filled of the bunch).
4. Return of the Jedi (Nice conclusion, although a bit lacking in particular areas).
5. Phantom Menace (It was a little silly and I personally saw the young Anakin character a tad annoying).
6. Empire Strikes Back (Probably the most overrated of the bunch. I get the whole stunning revelation of "Luke, I am your father!" bit, but if people look past that part, it isn't really that great in many aspects).
Alright, I know I'm going to receive a lot of ire for this post, but I have never seen a Star Wars movie front to back. I've seen bits and pieces of some, wanted to see it, but never really gotten around to watching.
I guess the main reason I never watched them is because of the crappy remakes that they make every couple of years that I'm afraid of running into.
My list is...
1. A New Hope- just EPIC
2. Return of the Jedi- Great ending
3. The Phantom Menace- Two things, Darth Maul and Liam Fucking Neeson
4. Empire Strikes Back- Not enough action for me, but best plot twist ever
5. Revenge of the Sith- Darth Vader awakens, but Anakin is kinda whiny
6. Attack of the Clones- Anakin acts like a butthurt child too much
That's just my personal opinion though.
The amount of Revenge of the Sith endorsements is a little disturbing, as pretty much all of those prequels were awful, but for me it is definitely Empire.