Doctor Who: Ranking All 13 Doctors From Worst To Best

Doctor Who's first regeneration was one of the biggest tests the show has ever endured. There were no guarantees that completely switching out the lead actor would prove a fruitful move, but now, all these years later, it clearly was.

And that's because Troughton brought something fresh to the role. By going from the First Doctor's grumpy grandfather to the Second Doctor's perkiness and fun-loving attitude, this version set the standard for the archetypal Doctor that most audiences identify with today: brave, wise, ruthless - when necessary - but playful and kind.

Troughton also had a terrifically unique look about him, with his huge mop of dark hair, big button nose and scraggly collar giving him that "looks like a human, but still feels alien" quality, an effect that many future Doctors would aim to replicate with their own outfits.

The Second Doctor is often cited as a major source of inspiration for many of his successors, particularly Smith, for whom Troughton is his favourite. That's a testament to the strength of his performance, and despite some admittedly uninspired stories, the Second Doctor shined throughout his entire run.