6. The Third Doctor To The Fourth Doctor
Another swift yet peaceful regeneration, the Third Doctor shares a few tender words with Sarah Jane before lapsing into unconsciousness after he absorbed 10 years of radiation poisoning after getting lost in the time vortex. The Brigadier utters the famous words "Here we go again..." as Jon Pertwee's "old grey model" fades away to reveal the bonkers bonce that is Tom Baker. While the regeneration is subtle, it is perhaps one of the most memorable of classic Doctor Who. The lack of drama and tension makes for a scene which allows fans to experience the sadness in losing such a wonderful Doctor in Jon Pertwee and then rejoice in gaining one of the most definitive actors to have ever taken on the role. The effects, aged though they may be, manage to hold to up to today's standards due to their inherent simplicity and so the scene is just as enjoyable today as it was back in 1974. https://www.youtube.com/watch?v=snl6LqFrr1A