For my main fursona, Sigurd Volsung
Beautiful Freak by the Eels
http://www.youtube.com/watch?v=niAW1f8xTc4Reason why is that I wrote in a story that my fursona hates the way he looks. He's a wolf with a tiger's stripes and his tail can't make up its damn mind on what it is. The tail looks like an overly long wolf's tail but instead of just wagging it slashes around and twitches like a feline tail. The fur that he marries is the one who gives him his theme song.
For my other fursona Brisbane it's Don't Worry be Happy by Bobby McFerrin (if you don't know this song you've been hiding uder a rock for your entire life. But I'll post a link here anyway
http://www.youtube.com/watch?v=yv-Fk1PwVeUThe other thing that works for Brisbane is just about anything that is really mellow, despite the fact that he is about the size of Shaq, all he wants to do is be very, very mellow