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.