Well, let's see, let me go ahead and start making my list of guesses. So far there has been (in alphabetical order):
Sean Astin
Brad Dourif
Bernard Hill
Sir Ian Holm
Christopher Lee
Sir Ian McKellen
John Rhys-Davies
So many guess, so many hopeful guessers, and yet, no one has it.
Try Again!!!!
EDIT: Hang on, is Ian Holm really a "Sir"? Cause I didn't know that. Hmm....