I'm throwing my answer in with Rooster, 3,4,5,6 were the best. They complete the entire storyline. Best of luck to you!
The first star wars movie I watched was in 2007 or so, I think it was the Phantom menace.
Then I watched the two movies after phantom menace) I really liked them but they gets second place
The original was way better
P.S: Cant wait for the force awakens