For a headset I prefer the in-the-ear type, using standard foam earplugs. The NRR numbers are better across the board than any ANR headset, and especially in the higher frequencies. They're also far more comfortable in every way.
Now that I have to wear a helmet, which I detest, I'm using CEPs, Communications Ear Plugs, which are essentially the same thing as the in-the-ear headset, but made to go under the helmet earseals, and plug into a jack installed in the shell. The noise level with these is actually higher with the helmet on, for some reason, probably because the shell concentrates and ducts the noise into the ears. I've checked it by removing the helmet, leaving the earplugs in, and the noise level actually decreases when the helmet is removed. I F&*(*^G HATE HELMETS!!!!!