This thread is for everyone to put their top 15 or top 10 favorite NPCs in Skyrim. This only includes named NPCs, not random ones (so guards, imperial soldiers, and enemy types do not count). Everything else, daedra, companions, random civilians, etc. all count, so please feel free to add your opinion. Now here is my list, in no particular order:
Serena (She reminds me in many ways of one of my closest friends, at least in terms of personality. Also pretty badass)
Balimund (He was one of the first NPCs I befriended. While there is not much special to his character I have always seen him as a good friend)
Teldryn Sero (While a bit annoying at times, the character perfectly pulls off the "grizzled merc" feel. His cynical attitude and experience really help sell the feel, and he seems loyal while still remaining professional and objective)
Paarthurnax (Definition of badass. Awesome voice, cool personality, and very helpful. Just an awesome NPC all around)
Vilkas (I know a lot of people were expecting Varkas [who I also am a fan of] on here instead, but Vilkas is a great character in his own right. He seems to be the most level-headed one amongst the Companions, and while not as strong as his brother, he is intelligent in his own right, and can still wield a sword pretty well himself)
Sheogorath (Definition of insanity. Remember the Joker's personality in Batman: The Animated Series? Now imagine that but slightly less sadistic [slightly] and with the powers of a god. He's incredibly likeable and entertaining, and always fun to be around, even when he uses your intestines for jump-rope)