Flandre's Theme is really fun and exciting to listen to. There are also some remarkably remixes by the many circles like ALICE'S EMOTION, COOL 'N' CREATE, dBu, SOUND HOLIC...
Though it may not be as popular as Flandre's Theme, I love Kanako's Theme (The Venerable Ancient Battlefield ~ Suwa Foughten Field) and Tsukasa, from Sound Online, did a good job with the arrangement as well the vocal assistance of Aki Misawa ('
Fallen Heaven' from the album
Trois Bleu)
Now for the topic, here a MAD featuring Clannad
And here the track, which was used in the video above (Remix by
IOSYS)