I really like my AKG K66 open back phones. Actually called semi-open backs.
I also have a pair of AIWA HP-X223's that are ok. They have a mute switch that has been a nice feature when I've used it. The problem with them is the fax-leather ear piece covering. Very little use, usually in a closed bin, and flaking.
Both are comfortable to wear, sound good, and the AKG's exhibit little ear fatigue. The AIWA's do get tiresome but are good for several hours.

Last edited by DakLander; 05/06/08 11:12 PM.