Tonight at 7PM in the United Kingdom Matt Smith, the incumbent lead from Doctor Who will appear alongside showrunner Steven Moffett to reveal the new lead actor in the role.
Names often mentioned for the part are Idris Elba, Peter Capaldi, Daniel Rigby, David Harewood, Rupert Grint or the second choice for #11 Chiwetel Eijofor. There also exists the chance The Doctor will regenerate into a female form, in which case Olivia Colman leads the odds as favourite.
Part of me wants to see Eijofor, Colman or Capaldi but I'd also be open to someone unknown. Who do you think or even hope to see in the TARDIS? Big names aren't impossible as John Hurtand Christopher Eccleston have proven.