Of Stephen Moffat’s most successful venture as a scribe for Doctor Who was the invention of the Weeping Angels, which first appeared in third series of NuWho. The episode was what was called the ‘doctor-lite’ episode, episode which were double banked with another to accommodate the Christmas special (I assume, feel free to correct me). This was a factor of the RTD era and is a lot less obvious with Moffat’s era, whether this down to better control of the shooting schedule or just done more subtly I don’t know, but I digress. The issue here is to do an episode of Doctor Who without having the Doctor and his companion in the episode to a great extent. With Blink, Moffat cleverly makes the Doctor the focus of the story while still being on a back burner. The way he does this with the use of the Weeping Angels trapping him in a different timezone and using a recording made in the past to have a third party rescue him. The episode won the DWM best of season award.
However I personally prefer the follow up Two-Part story with the Eleventh Doctor as it explores the idea of the Angels a bit more and looks into their quantum existence. There is also the subverted humour of an Angel using the larynx of a dead man in order to verbally communicate with the Doctor. We never learn of the Weeping Angels origin, the End of Time implies they are relics from the Dark Time of Gallifrey and a creation of the Timelords. Perhaps the ‘weeping’ is more then just they avoiding looking at one another (because being dismissive could have the same effect- though the Apathetic Angels doesn’t have quite the poetic ring to it), perhaps their existence as an Angel is a punishment and they are the Timelord equivalent of a Banshee…
I’d rather not know, it’s nice to have some form of mystery.