[Blix]

Twin Rova:
http://www.youtube.com/watch?v=TJbi4aCL3AA
The Final Day:
http://www.youtube.com/watch?v=DwtF3EMlFto
The Dark World:
http://www.youtube.com/watch?v=sslj06K-Nlw
And the clasic dungeon music
http://www.youtube.com/watch?v=cMssCMqMHuk

I'm trying to find the song played at the very first castle in LTTP when you get Zelda out of her prison. They used it for the last castle in Twilight Princess since (in both games) it is the hyrule castle theme. Maybe that's its name. But that one's awesome too.

Indeed. Here it is. http://www.youtube.com/watch?v=JbJbYFyklTg