BBC has put together a great page featuring video from all thirteen regenerations of the Doctor. It may take you a little time to watch them all, but this is a wonderful stroll down memory lane for fans of Doctor Who.
Matt Smith was the most recent to regenerate during "Time of the Doctor", which aired on Christmas Day. Peter Capaldi has taken over the role with new episodes scheduled to begin airing later this year.
Here are my cheers and jeers...
The Fourth Doctor (Tom Baker). I'm a big fan of the classic Tom Baker episodes. However, the Baker regeneration sequence features some kind of weird death shroud that absolutely ruins the transformation.
Most Touching Regeneration
The Ninth Doctor (Christopher Eccleston). Eccleston is perhaps one of my least favorite actors to play the Doctor. However, the goodbye between Rose and the Doctor is very memorable. His last words to Rose are quite touching. "You were fantastic. Absolutely fantastic. And you know what? So was I."
Best Entrance by a new Doctor
The Twelfth Doctor (Peter Capaldi). "Kidneys! I've got new kidneys!"
"Let's Get it Over With" Regeneration
The Second Doctor (Patrick Troughton). The regeneration sequence is so long that's you're almost cheering when the Doctor finally transforms.
The Tenth Doctor (David Tennant). Tennant is hands down my favorite of the Doctors. My eyes welled up as he looked around the Tardis for the last time and said tearfully, "I don't want to go."
Greg Belfrage is a lifelong Star Trek fan, Batman toy collector, sci-fi movie maniac and hopeless geek. He can be contacted at firstname.lastname@example.org.