I was re-watching that hilarious Dead Ringers Gladiator parody, and found out that they did several Doctor Who parodies, especially of Tom Baker. The best on is this one, where ''Four'' calls (the real!) Sylvester McCoy and McCoy seems to genuinly believe he's speaking to Tom Baker.
Best quotes:
McCoy: ''Are you all right? Have you been at the pub?''
''Four'': ''Oh yes, for several millenia''
''Four'': Canned food, five letters across.
McCoy: ''Spam''
''Four'': When I traveled through space and time, I had Leela and Romana''
McCoy: ''Oh yes, I fancied them, too''