Don't forget Tears for Fears. I love to "Shout" with them. There are so many wonderful pieces of music for every mood. I would make folders for my I-pod like "happy", "mad", "excited", "soothing", "spiritual", etc. You might also want a meditation section. I know that sounds so simple but when you aren't feeling so hot, simple is easiest.
I agree with the other posts. Get some comedians like Cosby, Foxworthy, etc. You need to laugh. The audiobooks or just good old fashioned paper books are always good therapy. I'm sure we can make a list of those too.