The John Williams score. It's about the only thing I can hold on an equal level with the OT.
Premise of Palpatine's rise to power.
Coruscant and the senate building.
Opening scene of ROTS. I would have liked it even more if it incorporated practical effects.
Naboo. Beautiful planet and city.
Montage at the end of ROTS.
Ewan McGregor, Natalie Portman, and Liam Neeson were good choices for their roles.