The Correct order to watch the star wars saga is: first episode IV a new hope, then episode V the empire strikes back, third one to watch is episode VI the return of the Jedi, then start over at the beginning with episode I the phantom menace and so forth till you end the saga with Episode III revenge of the Sith.

I know of a few people who started out with episode one and after the first three episodes thought the final three were lame in comparison. It is not his fault, he just made the simple mistake of not actually starting off from the beginning, this is a rare case where the first episode of the saga is not the first in the series.