Doctor Who: Every Regeneration Ranked From Worst To Best
7. The Fourth Doctor (Logopolis)
Tom Baker helmed Doctor Who for seven seasons - way more than anyone else - and left behind an untouchable legacy on British TV.
His final appearance as the Doctor came in the 1981 serial Logopolis. After teaming up with the Master to prevent the unravelling of the universe, the Doctor is betrayed by his nemesis, and ends up falling from a huge telescope to the ground below.
He is surrounded by his companions as The Watcher, a ghostly white figure who looks a bit like a toilet paper mummy, fuses with the fallen adventurer to begin his next metamorphosis.
The actual regeneration process isn't super impressive - Baker basically turns white for a second, and then Peter Davison appears gurning in his place. But it's what happens before this that's important.
While awaiting his fate, the Doctor receives visions of all his past companions. Though not as good as future callbacks, this moment is still very sweet, and proves just how momentous it was to lose Tom Baker as the Doctor.