Who'd have known that Mrs. Hudson was actually a man? And that scene where John practises giving oral satisfaction on a banana?! Cracked me up. I'll have to say, Bendybumble Cucumberbatch turning out to be Robert Downey Jnr. at the end made me happy. Great actors.
Now that was unexpected. Sherlock gets hit by a car on leaving the cemetery and wakes up in 1881, where he has to deal with a strange case that resembles one he worked on back in the first season? A stunning idea, and it's almost a shame that it only lasted for the first two episodes. I'm sure that concept could be extended to a longer series....
I must say, it was a master stroke to combine two shows - I never expected the TARDIS to show up while Sherlock was in mid-fall, allowing him to be saved from certain death, then returned just before the point of impact, being lowered gently to the ground and playing dead for Watson. Plus it allowed Benedict Cumberbatch to go off and be the Doctor for four years before returning to Sherlock without anyone noticing.
Well! I didn't see that twist coming! The fact that Sherlock Holmes is actually a 14 year old girl called Chantelle, who has spent the last 5 years in a mental asylum, and all the characters are her multiple personalities! Blew me away! I started to suspect something was not quite right when John moved out, and Barney the Purple Dinosaur moved in, but I thought, heck, I'll go with it. And by the time Sherlock and Barney had got married I was totally gripped! Moffat, you genius, you've done it again!
Wow. Bringing Keyser Soze into the third series was an inspired move, even though Sherlock traditionalists may have some reservations. Also, revealing that Watson was Moriarty in disguise all along - WOW. Masterful twist.
Also watch out for cameos from Harvey Keitel, Michael Crawford and Simon Pegg.