Just popped in here because I tried a new pair of noise cancelling headphones from Sony today. Bose have been pretty dominant, and possibly the best noise cancelling system, until now!
The Sony MDR-1000X is BY FAR the best pair in this category I've ever tested, and they are now the new yard stick in noise cancelling. They have lots of neat features, such as the right earpad is touch sensitive, so you can pause, skip etc. the music, and adjust the noise cancelling by touching the pad. Much more convenient than physical buttons you have no way of seeing unless you take the headphones off.
I compared them with the Bose QC35, and on "static" noise, such as train and jet engine sounds, they are pretty much equal of cancelling the noise. The sonys however are miles better at silencing other types of noise, such as other people talking and other sudden noises. The real neat trick though, is that you can adjust this, so for instance you can allow speech to come through, so you can have a conversation with someone, without taking your headset off. And it works incredibly well! The sound is fairly neutral and well balanced, with great depth and clarity. It also has a microphone, so works as a handsfree as well, and you can double-tap on the right earpad to engage Siri to make a call for instance.
I was very impressed. It also comes in a neat semi-hard carrying bag with a usb for charging, and a double 3,5mm jack adapter for airlines, and a 3,5mm jack cable. Pairing with bluethooth was somewhat weird, but they also have NFC so that wasnt' really an issue.
They're not cheap though at £400, but by far the best I've tried. Bose have some work to do to catch up now!