I love Charlize Theron as I'm never sure if it's her in a role! Similarly Cate Blanchett - both seem to manage to morph into their characters without excessive make up and change their voice too. I enjoy many of Sandra Bullocks films but she always sounds the same in each role, ditto Ann Hathaway.
I think Johnny Depp is a good actor although he does use a lot of make up in many of his roles. The likes of Henry Cavill, Alan Ritchson, Robert Downey Jr, Chris Hemsworth all seem to play the same role with different costumes! Although very beautiful to look at with or without clothes 