Can definitely recommend the Bose X. The noise attenuation isn't that much better than a decent pair of DCs or similar, but the real benefit is in the comfort brought about by the lightweight design and lack of clamping force.
Only problem I've had is that when the batteries are on their way out, rather than warning you it just seems to start switching the noise cancellation on and off intermittently. Anyone else have this problem? I'm using normal energizers.