I'm looking for very sad/dark classical music to add to my Ipod. I already have all the names that you will first think of, so tell me the second composer to come to your mind.

Classical music is by far the best music. All other types are eyesores (or should I say ear) compared to classical. That isn't to say that other types of music are bad. It's just that they don't compare to the beauty of classical.

If you mean classical guitar music, then I would strongly recommend everything from John H Clarke. (Find him on youtube, he has a wide selection from every kind of classical/flamenco, and most of it is his own work!)