Bryan Ferry
I am watching this film right now and have just seen BF. At first I thought "that actor looks just like BF", then I realised that it really was him.
For one thing, I didn't know he'd done any acting outside of the usual pop video promo thing. For another...woah, what a slimy, creep of a character. Not what I would have expected of him at all.
Incidentally, he was very convincing... shockingly so.