Series 9 gives us Peter Capaldi's second run as The Doctor and what a run it was. Even the pre-title sequence in the first episode can give a long-term fan a mind-blow. The opening two parter was an interesting one and although was unusual gave us some great appearances and easter eggs.
As the series went on I noticed that there wasn't really a continuing story-arc, you know that little scene they usually put in every episode that has a pay-off in the finale, there wasn't really one here. I really liked that; there are maybe one or two lines of dialogue you can look back on now as a foreshadow but all in all each story was self contained. I enjoyed there being a lot more two-parters as well, it allowed for a more paced plot rather than a rushed ending. All-in-all the majority of episodes I really enjoyed, making series 9 one of the best series since 2005.
Of course there were bad episodes, in my opinion The Girl Who Died, Sleep No More, and The Husbands of River Song were just dreadful. I know they have their fans but for me personally, I disliked a good portion of each of them.
In the end I think series 9 was one of the best series so far and Peter Capaldi is still an excellent Doctor, Jenna Coleman was good, as always, despite my dislike for the character and I rather enjoyed the finale, which is unsual for me and Doctor Who.