well, i don't own them, but i have no doubt that these are the best headset money can buy right now purely because they're a flagship audiophile grade headset made by one of the most respected audio manufacturers in the world with enough custom engineering to make high-street equipment look like kinder egg toys.
http://www.sennheiser.co.uk/uk/home_en.nsf/root/private_headphones_audiophile-headphones_500319
however, i would recommend getting the biggest drivers you can purely because it lowers distortion
the new corsair headsets have a very good power delivery across most ranges, but the actual headsets are rather flimsy
my friend and i both have corsair headsets and the bands broke on both of them in under a year
the structure is rather weak, but the sound engineering is impressive for the price-point
if you take good care of them, they may last longer
the ones i intend to buy next are:
http://www.superfi.co.uk/index.cfm/page/moreinfo.cfm/Product_ID/263
i have been doing allot of research on them and apparently due to the open backed nature of headsets like this the sound quality is vastly improved at lower levels meaning less distortion in quieter sounds and more crisp highs
possibly not the best for gaming, due to it's sound leak but it's a crime not to have an audiophile set plugged into my sound card ( asus stx )
also it doesn't have a microphone, but as anyone who has tried a shotgun mic set-up will tell you that's possibly a good thing, the tiny carbon / condenser mics in headsets are universally terrible anyway