I have a pair of Sennheiser PXC 350s... it's been 3 or 4 years, so you can obviously find newer Sennheisers out there, but I really enjoy them. I love flipping the noise-canceling switch when I'm in a plane, and they sound great.
That said, I tried a pair of Bose noise-canceling headphones a year or two ago while I was sitting with someone in an airport, and they definitely did a better job of reducing background noise. If that's a big concern, you should definitely try them.
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