2.) ANH - We would all love Star Wars even if this was the only film. 'Nuff said.
3.) ROTJ - Jabba scenes, death of Yoda, and the final battle outweigh Ewoks and the beginning of Lucas's downfall.
4.) TPM - Qui Gon and Darth Maul are fantastic. I still feel sad at the death of Qui Gon, maybe the only time I care about a character in the PT. Jake Lloyd, against all odds, the best Anakin in the PT (not saying much).
5.) AOTC - Rubbish, but didn't need to be as good as III had to be.
6.) ROTS - Maybe the most important film of the saga. Fails at all major/important plot tie-ups. Anakin's turn to Dark Side utterly unconvincing.