He is.....
every character he plays.
Seriously, every time I see him in a movie etc I NEVER recognize him at first. In fact I was showing Peter Pan to a friend of mine who never noticed that Hook and Mr. Darling were one and the same.
I know there are plenty of posts on how handsome he looks etc., but I think he is one of the most under-rated actors out there. I would rather see his characters and not recognize the actor underneath, than watch so called "celebrities" play themselves on screen over and over again.
Oh...and HELLO to Jason Isaacs!