Your favorite character? In books Sherlock but in BBC's adaptation, John
Your least favorite character?Mycroft (in both books and shows)
Favorite Arthur Conan Doyle story? Probably the Hound of Baskervilles
Favorite episode of BBC Sherlock/Elementary/Granada Holmes? My favorite episode is the first of season three. Seeing all the theories was fun and also the interaction between Sherlock, John, and Mary was just lovely.
I absolutely abhor Elementary, it's complete garbage in my opinion
Favorite actor who plays Sherlock Holmes? Doctor Watson? Moriarty? Mycroft?
Benedict Cumberbatch is an excellent Sherlock by looks but I feel that Basil Rathbone was the best Sherlock there ever was. For Doctor Watson I genuinely like Martin Freeman best. Moriarty is best done by Eric Porter. And since I have never been found of Mycroft I can honestly say I have no opinion in a favorite actor for him.