24. Spearhead From Space 7.1-7.4
This one gets a bit of a bump for being the Third Doctor's first story, as well being the first one in colour. But it is admirable for a handful of other reasons too. It highlights the Doctor's alien-ness as a medical doctor tries to help him through post-regeneration sickness. It is also an early example of seeing a companion, in this case the Brigadier, adjust to a regenerated Doctor. Here the Doctor displays his signature knowledge of other worlds, spouting off about the planet Delphon in his first properthat is fully consciousscene. It gives us a chance to meet companion Liz Shaw, a snarky, sceptical scientist. If all that is not enough, it is also the first story to feature the Autons, that race of living mannequins, and has an engaging subplot involving meteors. Finally, we are treated to another distinctive feature of this Doctor, his penchant for somewhat flamboyant transportation vehicles.
23. Wedding of River Song 6.13
Well being perhaps one of the most confusing stories Doctor Who has ever offered for the casual viewer to decode, this story's best feature is that it offers yet another notable consequence of trying to rewrite fixed time. Time effectively occurs all at once, and appears to also freeze, disintegrating outward from the point of the wound. The plot also features a monster who has plagued this version of the Doctor, the Religious Order of the Silents, and points the Doctor toward the-then mysterious planet Trenzalore. But most importantly the solution to resolving the wound in time sees the Doctor getting married, a culmination of so much romantic energy in Modern Who, thus finally cementing a relationship we had been waiting to see play out for years.