The Bose gives the best comfort and quality, in my opinion. The new A20 is good enough that on a recent trip, one crewmember who had the headset loaned it to two others to try out, and they bought one for themselves at the conclusion of the trip. Pricey, but worth it.
For those so inclined, I'd offer the QC-15 with a u-fly-mic as a worthy and less expensive alternative. It's a very compact and excellent set-up. It's the headset technology from which the A20 was developed, and the u-fly-mic is a very well-made, very robust set up.