I love Doctor Who. It was actually my girlfriend who got me into it. So far I've only seen the revived series, but I really want to watch the classic episodes.
SPOILERS:
Let's kill Hitler blew my mind. I can't believe River both killed and saved the Doctor in one episode. It still seems that a young Melody kills him. It also seems to show that the Doctor and River's time lines aren't completely back-to-front, since the Doctor has seen her regeneration and death and they haven't mentioned any of their other adventures. Also, finding out more about the Silence. I can't wait for more.