I use Pilot and find them real comfortable,good sound and not prone to popping + fair passive protection, & with interchange cords, rechargeable batteries, cell\ music input real flexible if changing types of aircraft.
www.pilot-europe.com/products/aviationcat.php?prodtype=ANR_Headset
I also have a set of Mach 3 with custom ear moulds which are ok to, no anr but the isolation is said to be the same or better, than anr as it should suppress all\most of the damaging audio spectrum.
The custom mould man said they will not sound as quiet as anr but will cut out the high freq 1000 \ 1800 kHz better than any anr, and with the same or better protection at lower frequency's