I'm not sure if this particular piece of dialogue was ever recorded but in the Marvel comic adaptation of TESB Vader counters Luke's line of "You'll find I'm full of surprises" with "And I too".

I love this as it serves a duel purpose, firstly Vader counters Luke's moves with very little effort, so it serves as a warning to Luke, in Han's words to "Don't get cocky".

It also foreshadows the big revelation to come.

If it was never recorded perhaps it's possible to create the line by editing the line together from other sentences that Vader has said.