Can't settle on just one here's a couple
"Your feeble skills are no match for the power of the dark side. You will pay the price for your lack of vision." Emperor ROTJ
"Indeed you are powerful as the Emperor has foreseen." Vader ROTJ
"It is unavoidable, you like your father are now mine." Emperor ROTJ
"We'll I should be, someday I will be, I will be the most powerful Jedi ever." Anakin AOTC
"You have been well trained my apprientice, they will be no match for you." Sidious TPM
"So be it Jedi" Emperor ROTJ
let me top I can go on and on
As soon as C3PO has something cool to say, i think he'll stay out of this. Ya know, i always wished he would have told Luke about his father in a good light. As far as Anakin being the one who made him and just tell him how he was before hand....but ok.....
"where is everybody? C3PO"
I say, were you looking for me?
C3PO/ROTJ