What headphones mixing/mastering?

Hi. I consider to buy pair of good cans for mixing/mastering. I have read lots of posts about it but time goes by so quickly and companies produce new or improve older models and posts could be already outdated.

Therefore I have a choice of a few models at similar price range so I'm a little bit confused now...
I had borrowed from my friendly radio station Beyerdynamic 770pro (250 Ohm) ones and I was quite impressed - extremely comfortable and sounded pretty good but didn't like boomines and very upfront midrange.

Generaly I use M-audio or KRK monitors to check final mix but mostly I use headphones during mixing stage so I need the perfect closed or semi open headphones. Unfortunately each make and model of headphones sounds different so I made my "wish list" and need your help guys. The question is: which ones for metal/rock mixing/mastering?

ATH-M50s
Sennheiser HD 280 PRO
Sony MDR7506
Sony MDR 7509HDs
Beyerdynamic 770 PRO
Shure SRH840
KRK KNS 8400
AKG K240 Studio (semi open)
AKG K 702 (semi open, the most expensive but acceptable :heh:
Check out AKG K-240 MKII instead of Studio http://www.akg.com/K240+MKII-1039.html?pid=1194

In my opinion you should probably look for semi-open models as they are a compromise between closed and open. Closed headphones are more for performing players who need sound isolation.
 
I float between ath-m50s, senn hd600s and shure srh 440s. Will probably pick up some beyers in the next few months just so I an keep switching it up. They feel real comfy. I wear glasses so some cans are quite uncomfortable to wear for extended periods, esp the audio technicas.
 
DT880 are unusually comfortable. I wear glasses as well and soft, velour earpieces helps a lot :) Tonally - bass is quite flat and theres no hype at all so its easy to overload your mix with exaggerated low end. After few hours I "learnt" frequency balances and after make some comparison to my KRK monitors - now is perfect for me.