http://www.ultrasone.com/ they make reaaaly high end gear. they design them so you get less ear fatigue as well wich is great. I have a pair from the "pro" series for my studio, i havnt tried anything from there dj line. they are realy natural, realy comfortable and the wire unscrewes so if it gets shredded in there u can just swap it out. mine also came with extra ear pad thingies (idk the name for them but they are fuzzy!!). uhh what els can i say for them. oh they bass responce on mine isnt as kicking as i'd like it to be, but i think that may be becuase the rest of my gear is a little muddy so i mix a little thin. SPEEKING of wich, they have a HUG range of frequencies they can make. realy articulate on the high end, but never a ton of noise cancellation. okay theres my little review for ya! haha.
I also use a pair of ath m40fs they are... meh. comfy, but they are muddy, not very good on the top end.
i wouldnt recomend the ath m20.... thy were toyish, 2 light 2 small, no pop. they were just dog crap.
i'd say do some research on ulstrasone's dj series, i know there head phones can be expensive ( they used 2 have a pair that was over a grand, i got mine for 700) but they are great.