Colin Baker
I've got Colin's signature a few times. The first, I wrote to him and he signed my copy of Timelash. Then I bought a few of his books and they came signed (this was through Hirst Books, though since them they have got a big reputation for being very unreliable, not sending purchases etc so avoid that company!!!). And finally, I met him at a convention in 2013 and he signed the Revelation of the Daleks DVD cover