If you are a fan, there's a quick little quiz that tells you which Doctor is most like you. You can take it here.
My result was exactly what I expected it to be :)
The Tenth Doctor is the tenth incarnation of the fictional character known as the Doctor seen on screen in the long-running BBC television science-fiction series Doctor Who. The Tenth Doctor generally displays a light-hearted, talkative, easy-going, witty and cheeky manner, but combines this with a somewhat egocentric sense of unstoppability when facing his enemies. He is perhaps as ruthless and dangerous as his seventh incarnation ever was, although much less inclined to complex schemes and set goals.