Headphone I can stand for more than 1 hour

I agree with Sidssp, the 580 and 600 are very comfortable. For me they were the most confortable and best sounding of any traditional headphone I tried. Problem was I needed isolation (580 and 600 are open-air type) so I went with the Etymotic ER-4P. You might consider the Etymotic if you have problems with traditional headphones, but be forewarned they can't really be used while you are moving due to microphonics and some people do not like anything stuck in their ear!

Try MB Quart they are very light and comfortable. Mine are MB Quart 250. Sound wise I found them to be very close to Sennheiser HD580's and Beyerdynamic DT990. I fall asleep with them on all the time.
Good Luck

Sony makes a very comfortable open ear design-well ventilated.

Consider also a non-fatiguing headphone amp (tube rolling helps), and most importantly, some kind of crossfeed circuit which will reduce long run fatigue.

I have the Senn 590's and they are very light and comfortable. I've read several other threads which indicate the 570/590's are more comfortable then the 580/600's line, but I only had the 600's on for a short demo, so I can't really comment more then saying that they did seem a little heavier IMO.

Gee I kinda like my Stax Pro Lambna's, cost me $700 back in '90 and still going strong, I could never go back to dynamic type headphone the electrostatic is too revealing. They are big but not uncomfortable. Stax dedicated headphone tube amp is a must.. improvement over their voltage conversion boxes. Model 007t or something like that is what I use, sounds great.