Well, I'm pretty excited. Today I received my set of Bose QuietComfort 2 headphones. They're a bit on the pricey side, so I've been saving for a while, but I am in love with them! The phones are awesome and extremely comfortable. Even before putting in the single AAA battery it drowned out so much of the ambient sound I could tell I was in for a treat.
Then I put the battery in, switched 'em on and I was in an auditorium. Perhaps appropriately, the very first musical piece I played once putting them on was Beethoven's 9th Symphony 
The phones fold down nicely and came with a great hard carrying case which makes them perfect for traveling. In fact the primary reason I purchased them in the first place was because of travel. I travel quite frequently and airplane noise really wears on me. That, and the fact that I had to turn my speakers up very high just to hear over the engine howlings, thereby adding more noise and stress prompted me to look into a noise-cancelling alternative. Though I haven't yet taken these on a test flight (I will on Sunday), I can tell that I'm already going to be very pleased with the result.