The virtual idol Hatsune Miku seems to be extremely popular at the moment, particularly at covering anime songs and performing video game sounds/BGM. People are posting loads of videos to youtube.
Here are some of my favourites that I've found so far:
GAME:
Dancing Mad (Kefka battle) from Final Fantasy 6
Gradius 2
Konami retro mix
Castlevania
ANIME:
Shangri-La - Soukyuu no Fafner. I love the way they got it to do an impersonation of the lead singer of "angela".
Zankoku na tenshi no thesis - Evangelion.
Mizu no Hoshi e Ai wo komete - Zeta Gundam
Tobe! Gundam - Gundam 0079
Captain Harlock
Ai Obotetemasuka - Macross: Do you remember love? (WARNING: Contains spoilers!)
Geki! Tei ~Saishuushou~
The Sakura Taisen 1 and 3 themes together.
Not such a great version but I like this song. ^_^
TOKUSATSU:
Battle Fever J
Denjiman and another version
I like the way they've kind of used her as an instrument rather than as a singer for the videogame remixes. The "angela" song is the best anime cover version by a long way, I think. Not a patch on the original, but I like what they tried to do - it's very ambitious, and is a good result. Some of the others are just plain funny. :D
