Bose QuietComfort Headphones
These Bose headphones are fantastic for blocking out the noisy drone of jet engines during long flights. They are also very comfortable on your ears, so you can wear them for long periods of time. I also tend to wear them in the office which allows me to focus on my work without being distracted by the sounds of a typical office.
These sound GREAT and are quite a bit less expensive than the QC2/QC3 phones. And they actually do a pretty good job of blocking outside noise.
These high-end headphones from Bose offer a full range of sound. They have soft silicone tips that rest comfortably in your ears. It includes color-coded removable tips of various sizes for a custom fit.