One of my favorite climbing songs of all time is "Preliator" by Globus (from their album Epicon). I use this type of music sparingly in my classes, but I really love coaching my classes through songs such as these. The music provides so much motivation and just begs your legs to climb. Globus' music has been described as 'symphonic rock' or 'symphonic metal', and this particular song is epic enough to have been used in several movie trailers. Check out the live version here:
I was recently turned on to another song from the same album called "Europa". I'll be using this one as a seated climb at around 70 rpm's, adding gear every minute. The music slows briefly at 2:10, but don't let that slow your climb. Continue on and finish this nearly 4 minute climb strong! Enjoy!