I never watched much Doctor Who before the 2005 revival, so I never had a favorite Doctor. In fact, if you'd asked, I probably couldn't have pictured anybody except that-guy-with-the-really-long-scarf-you-know-who-I-mean. So my first Doctor was Christopher Eccleston, who I thought was brilliant and left the series too soon. I was not a fan of David Tennant's spastic squinting, and stopped following the show after his first season.
But when Tennant was replaced by Matt Smith, I knew I could never be fair to him however good he was, because my friend Willow had ruined any future Doctor for me: she passed along a suggestion that the perfect Doctor would be played by Chiwetel Ejiofor. And it's absolutely true. Watch him back to back in Serenity and Kinky Boots to see him show the science fiction chops, the cool competence, and the utter love of humanity that need to spin together to make a proper Doctor, and it's hard to be excited about anybody else getting the role.
It looks like I'm not the only one who thinks so.