I don't know if it's the best, but I'll say this. I tried one of the cheap (lowest end) Motorola ones and I just couldn't do it. People couldn't understand me, said it was noisy, said I sound 'distant' and like I'm on a speakerphone.
It was crap.
So, then we tried a Jawbone. It was amazing. It worked. I could hear. People couldn't tell I was on a bluetooth headset. The noise cancelling WORKS. I tested it myself with my wife using the jawbone, she went on the freeway and rolled down the windows, clicked it on and *boom* it was quiet.
I couldn't tell she was in a car at all.
I have to admit I thought the Jawbone was overpriced gimmicky garbage, but nwo that I've tried it I'm a convert. It's an awesome headset.
Now, are there other ones that are just as good? I don't know. I've only tried the worst, and the Jawbone.
But, I'm getting another Jawbone, my wife stole mine.