I've been a fan of Pandora since 2006. It is by far the best online internet radio service out there. They say it best:

music should move your consciousness, and more importantly your subconscious, to an elevated level while you listen...so that it positively affects you and the enlightenment felt during the listening of the music brings your spirit and being into an utter peace with side effects of happiness, contagious to those interacting with you. Unless you feel like a part of the music possesses some sort of connection with you, in any degree whatsoever, then the music is just background music to you, though others may feel that special connection. Music is the ultimate pacifier for most any emotion: happiness, sadness, depression, stress, up-beat/energized, feelings of self empowerment, feelings of worthlessness, love, hate, envy, confusion, solutions, etc.