Peter Davison played the role of the Doctor in Doctor Who from 1982 to 1984, during the Fifth Doctor era. He portrayed the Doctor for three seasons.
Peter Capaldi
The 1st Doctor William HartnellThe 2nd Doctor Patrick TroughtonThe 3rd Doctor Jon PertweeThe 4th Doctor Tom BakerThe 5th Doctor Peter DavisonThe 6th Doctor Colin BakerThe 7th Doctor Sylvester McCoyThe 8th Doctor Paul McGann The (8.5 War Doctor) [actually the real 9th] John HurtThe 9th [actually the 10th] Doctor Christopher EcclestonThe 10th [actually the 11th and 12th] Doctor David TennantThe 11th [actually the 13th] Doctor Matt SmithThe 12th [actually the 1st of the new 12 count regenerations] Doctor Peter CapaldiRichard Hurndall replaced William Hartnell (who had died) in a special episode in 1983 called 'The Five Doctors'.
Mike Davison debuted on October 1, 1969 and played his final game on October 1, 1970.
Scott Davison debuted on September 4, 1995 and played his final game on May 30, 1996.
The production team have not started looking for someone to play the 12th Doctor as of yet.
The actor who plays the Doctor in Doctor Who varies depending on which incarnation he is on. Currently, the actor playing The Doctor is the endearing Matt Smith, and the one before him was David Tennant-my personal favorite. Here is a list of all the actors to play the Doctor, each of them brilliant in my opinion. William Hartnell - 1st Doctor Patrick Troughton - 2nd Doctor Jon Pertwee - 3rd Doctor Tom Baker - 4th Doctor Peter Davison - 5th Doctor Colin Baker - 6th Doctor Sylverster McCoy: 7th Doctor Paul McGann - 8th Doctor in the 1996 Televison Movie. David Tennant- 10th Doctor Matthew (Matt) Smith- 11th Doctor
Peter Capaldi (the Twelfth Doctor) has been playing the Doctor since 2013, when he took over from Matt Smith.
For however long she wants.
Sylvester McCoy, the Seventh Doctor, and David Tennant, the Tenth Doctor, are the only Scottish actors to have "officially" played the Doctor, though many companions and side-characters have been Scottish. UPDATE: As of 2014, Peter Capaldi has taken on the role of the Twelfth Doctor becoming the third Scottish actor to "officially" play the Doctor.
For three years 1963 - 1966
No. According to IMDB, Peter Graves never guest starred on Gunsmoke.
Scott Davison debuted on September 4, 1995, playing for the Seattle Mariners at Kingdome; he played his final game on May 30, 1996, playing for the Seattle Mariners at Kingdome.