While everyone says you shouldn’t mix your music on headphones, if you decide that you want to do it that way anyway (or you at least want to get a rough mix down with headphones) then you should definitely consider Audio Technica ATH-M50 headphones.

They are widely known for being great mixing headphones (because they accurately represent the music rather than coloring it in some way) and also for being very comfortable to wear.

I recommend buying them from buy.com because their prices are hard to beat.

In fact as of this post they are almost $30 cheaper there than they are on Amazon. But if you would rather shop at a music oriented store you can also buy them online from GuitarCenter.com or maybe best of all you can search for a great deal on EBay:

AUDIO-TECHNICA ATH-M50 STUDIO MIXING HEADPHONES US $79.99 (0 Bid) End Date: Thursday Feb-23-2012 18:58:54 PST Add to watch list

Audio-Technica ATH-M50s/LE Professional Silver Studio Monitor Headphones US $169.00 End Date: Thursday Feb-23-2012 19:33:33 PST Add to watch list