In no particular order:
Admiral Ackbar
Luke Skywalker
Palpatine
Darth Vader
Grand Moff Tarkin
honorable mentions:
That droid that talks to C3PO in Jabba's droid dungeon
The rancor keeper
And, although no one asked, least favorite:
Nien Numb
Boss Nass
Nute Gunray/ Lott Dodd
Elan Sleazebaggano
That female Asian Jedi in the Geonosis Arena that makes all these stupid movements with her hands. God, she pisses me off.