I'm not too much of an audiophile, but I decided one day that I really wanted one of those huge cans that you always see the pros using. Upon some deliberation, I decided to pick up a set of Sennheiser HD-570s.
After breaking them in, I found the sound quality to be fantastic. Two things are worth noting before going on; the headphones themselves are not closed/sealed. They have this pourous open look, which is supposed to enhance the sound, but in exchange, it is fairly easy for anyone near you to hear what you are listening to. Also, without a strong driver to drive these headphones, you will not get the full aural experience. Nevertheless, I tried using them on weaker drivers such as my computer and an MP3 player, and they still sound fantastic.
They're immensely comfortable as well. The only thing I can fault it for as that they might be light on the bass - but other than that, they are a great pair of cans.