5. Multi-Doctor Story
The 50th anniversary episode brought together three Doctors for an exciting story about what really happened in the final day of the Time War and, while it could have been about 30 minutes longer to help open the story up, it was a great episode overall. Many multi-Doctor stories give fans a bit of nostalgia along with the excitement to see which personality(s) clash with whom. In the search for Gallifrey, the Doctor becomes increasingly incensed, believing it's out there but not being able to locate it. Well, who better to bounce questions off of than yourself? The Doctor could find a younger version of himself in the past and ask that Doctor to help him find Gallifrey in the present. Many fans would love to see Paul McGann's Eighth Doctor return for a spin on the television to help Peter Capaldi's Doctor in the search, but just about any of the Doctors will work in this scenario.