I have a couple of Bose X headsets and as IO says they are the best thing money can buy. I have used them in everything from Open Cockpit to a CJ1.
I use the noise canceling non aviation headsets with my iPod and for airline travel as well.
They do not have the best passive reduction but then thats not what they were designed for! They weigh nothing and are a tough enough for a considerate owner but certainly not for a flying school.
Mine has more than 2000hrs of use on it and still looks like the day I bought it.