Rather short list:

- Obi-Wan. Ewan McGregor was a great choice for casting, and he's one of the only good actors in the films.

-Good Villan Concepts. While the actual characterization of these guys leaves a bit to be desired, the concepts alone for most of them are enjoyable enough.

-The Effects of TPM. I actually think the sets and effects of this film are better than the other two, if only because they look more realistic.

-Certain parts of the score I find good, but to be honest most of it I find rather bland.

-Attempt at emotion in ROTS

-The whole Palpatine plot is rather well done.

That's about it. I'll let you know if I missed anything.