Episode S3E10 "Blink"

This was the first episode of the new Dr Who I saw. And it was at the suggestion of my 70 year old mother that I ended up watching. And its no wonder, this episode is great. Wonderful writing from Steven Moffat. This single episode (and the lovely Carey Mulligan) got me into Doctor Who.

Sally Sparrow (Carey Mulligan Wiki IMDB)