5. Bill Cosby
That's right, Paramount Picture's second choice for the Doctor's U.S. debut was none other than Bill Cosby. With recent speculation of a black Doctor, it seems it could have happened a lot earlier than expected. Bill Cosby was a big name actor in the 80s and, like Michael Jackson, would've brought a new level of stardom to the Doctor. It's hard to say if this would have been a good or a bad thing, but I'm going to go with bad. Part of Doctor Who's charm was how underrated Classic Who was and still is. Granted, Cosby has the ability to spew gibberish (pudding!) as well as any actor to take the role. His incarnation would have played father figure to his companions (think William Hartnell meets Dr. Huxtable) and the classic Cosby sweaters would make for a great, iconic Doctor Who outfit. I just don't think Bill Cosby could be taken seriously as a 900+ year old time traveling alien and I think American viewers would agree.
4. Richard Griffith
Richard Griffith is one of the few people to actually be offered the role twice once for the role of the fifth Doctor and a second time for the role of the Eighth. He had to turn down the role the first time due to scheduling conflicts and before he could be cast as the Eight Doctor the show was ended. Griffith's Doctor would have been a warm, inviting Time Lord. Much like his role of Hector in The History Boys, his companions might tease him but have a deep love and respect for him although he probably wouldn't feel them up on the back of motorbike. Don't cross this Doctor though, or you'll see the wrath of Vernon Dursley. In truth, Richard Griffith may have made a great Doctor. His warm tenderness might have given the Doctor a connection with his companions that he and they have always wanted. He also might have been a bit too passive, a characteristic I don't like seeing in the Doctor. But mostly, if he had been cast, Griffith wouldn't have taken any of the roles we've grown to love him in like Vernon, Hector or Uncle Monty in Withnail and I.