Ooh, I think I'll take advantage of the +5 addition to include some fanworks, since I didn't fit any into my original nominations.

Fanvids:
Grapevine Fires (Star Trek pan-series) by skywaterblue. This vid rather summed up my feelings after seeing the latest Star Trek film. Emotionally powerful, I thought.

Cosmic Love (Supernatural) by aquaenumen. One of the best SPN vids I've ever seen. Not just well done, but beautifully done.

Filk:
Ballad of the Lone Centurion (Doctor Who) by nextian. I've never seen anything quite like this. There are two versions of the song, which are presented in nextian's post as traditional folk songs from the universe on which Rory Williams guarded Amy in the Pandorica and became a myth that people told. The entire post is written in-universe, with historical geekery added in.