AKG K701
I have them for about a week now and they start to sound better and better every hour I listen to them. Make sure you don't judge this wondefull headphone the first time you listen to them, they realy need some good burn-in time. I read on the internet it needs up to 300 hour!
I use them for about 4 to 6 hours a day now, and it's getting better and better, already beating the also wonderfull AKG K240 Studio headphones I have.
The detail in the low frequencies is just amazing. It's not bass heavy, but it just sounds so wonderfull and it's present!! WOW!! well.. everything about this headphone is wonderfull!!