Motorola MotoPure H12
I am hard to please with Bluetooth. I've used the Samsung WEP200 and WEP500, the Motorola H700 H500 H9 S9 H680, the Jabra BT2010, and the Plantronics 665 (just to name a few) and I could never get my girlfriend to stop complaining about background noise or static or whatever.
I've been using the H12 for several days now and the complaints have completely stopped. A few days ago I told her I'd been using it to talk to her the whole time (as a sort of experiment) and she told me that she honestly thought I'd been using my phone normally without a headset at all. The clarity on the other end is fantastic (I've had her use it and call and talk to me) whether you're in your car with the AC on (I've even tried it with the windows down and it still performs very well) or walking down the road with the wind on your face.
Very comfortable with a number of options with how to attach it, you can use the clear ear hook that it comes with and the smallest ear cushion if you hate in-ear headsets, or you can use the larger ear cushion if you hate the over-the-ear attachments like I do.
It still has the normal Bluetooth flaws, such as range or putting objects between the headset and the phone, etc. but it is the most acceptable headset that I have used to-date. It's a bit pricey (Sprint is retailing it at $129.99) but I think it's worth the quality. Consider that the Plantronics 665 retails at the same price and try both of them, you won't be willing to accept the Plantronics after comparison. If you're looking for a good one, give this headset a try!!!