A few things:
Special effects
The fact that clones evolved into Stormtroopers
The lightsaber duel in TPM
Obi-Wan - Jango fight on Kamino
Most of ROTS except that Chewbacca was in it, wtf? And Grevious wielding sabers was silly.
Some scenes of ROTS were gold though, like:
Anakin finding out Padme is pregnant
Palpatine telling Anakin about Darth Plegous or whatever his name was
Obi-Wan telling Padme about Anakin turning to the dark side
Obi-Wan cutting Vader into bits and the dialogue that followed and
The last four scenes that show where everyone ends up. The Padme funeral scene is the only scene in Star Wars that almost chokes me up lol.