I will admit that I was dreading getting back to that point, and with good reason. I still feel that Seasons Eight and Nine are the weakest of the seasons that I have seen, despite the introduction of Missy (played by the remarkable Michelle Gomez)--who quickly became one of my favorite Doctor Who characters. Only right at the end of Nine, with "The Husbands of River Song," did the show seem to find the right balance again.
... And then it got really good again!
Now, David Tennant is still my favorite incarnation of the Doctor, and the plot line with Matt Smith and the Ponds (Karen Gillan, Arthur Darvill, and the sensational Alex Kingston) is my favorite story, but Season Ten might just be my favorite season ever. Starting with "The Husbands of River Song" (which I truly count as the Christmas Episode between Nine and Ten) and ending with the two Doctors in "Twice Upon a Time," this season managed to get back to the wild goofiness, yet thought-provoking drama that I love about Doctor Who. It also did more, I feel, than any previous season in tying back to the original run of Doctor Who. Even though I never really watched the original, the fact that they were clearly paying homage to the past was a very nice touch--especially for a show involving time travel.
Although Bill (played by Pearl Mackie) is not even in the running as my favorite companion (even in this season thanks to the above-mentioned Missy and Matt Lucas' wonderful performance as the still mysterious Nardole), the character of Bill was perfect for really bringing out Peter Capaldi's true ability to play the Doctor. Bill was an everyday person, yet special anyway. She wasn't part of some complex time-paradox plot, nor destined to save the world (let alone universe). She was just true to herself and interested in learning everything (kind of like one of my favorites, Donna Noble--played by the hilarious Catherine Tate). Thus, she grounded Capaldi's Doctor in ways that Clara's Impossible Girl could not.
Nor were the plots tremendously convoluted and powerful (Sure, there was the running mystery of the vault, and sure, the puddle came back into play, and the multiple Masters near the end was fantastically well done.). However, with Moffat no longer the showrunner, there weren't the same "gotcha" attempts that plagued seasons Eight and Nine (Honestly, they were just trying too hard.). Still, the stories of Season Ten were engaging with not a single "I didn't really care for that one" among them. More importantly, they had heart to them, strong themes that tie to what it means to be human, good, and kind.
I just really enjoyed this season, and because of it, I place Capaldi just slightly below Tennant as my second favorite incarnation of the Doctor.