2 can be argued the worst, but the Genosis stuff and whole world building was pretty cool no? I feel like while it was LAME the love story and stuff, at least they HAD a clear direction and story, unlike the sequels imo, where they would just throw random stuff in that was star wars related and dismiss any coherent story.
Prequels were pretty straight forward. Origin of Vader, friends/characters attached to that story, Jedi Council, Emperor Palpatine rise, young-er Yoda, Obi-Wans prequel, the final purple lightsaber, etc.
The sequels were just messy.