Star Wars Episode 1
1. Ian Mcdiarmid as Senator Palpatine/Darth Sidious
2. Liam Neeson as Qui-Gon Jinn
Star Wars Episode 2
1. Ewan McGregor as Obi-Wan Kenobi
2. Christopher Lee as Count Dooku
Star Wars Episode 3
1. Ian Mcdiarmid as Chancellor Palatine/ Darth Sidious
2. Ewan McGregor as Obi-Wan Kenobi
Star Wars Episode 4
1. Alec Guinness as Obi-Wan Kenobi
2. Peter Cushing as Tarkin
Star War Episode 5
1. David Prowse/James Earl Jones as Darth Vader
2. Mark Hamill as Luke Skywalker
Star Wars Episode 6
1. Ian Mcdiarmid as The Emperor
2. David Prowse/James Earl Jones as Darth Vader
Good list, I'd put Hamill in place of The Emperor in Return....it's got my favorite Luke/Vader scene, and not the fight. It's when Luke surrenders and he and Vader are walking down a hallway talking.
My favorite seen is when The Emperor is seducing Luke to the dark side which makes luke use the force to grab his lightsaber to attack him which leads to the Vader/Luke battle.