I have a few bluetooth requirements. I like the behind-the-neck cord design and over the ear design headphones.
I own 2 different ones:
Cheap: I got some MPow Cheetahs from Amazon... $23-27 These are great, but their design has screws showing on the outside. They will eventually get sweat inside them and on the earpieces and potentially corrode. I've had mine for almost 1.5 years and sweated in them almost weekly...mine are still good, screws are rusted...but they work.
My wife bought me the Powerbeats 2 from Target @ $90 on sale. They are more rubberized and not as stiff. The controls to change tracks and adjust volume aren't as good as the MPow Cheetahs, but they're somewhat comfortable and appear to be more sweat resistant. I've only run a few half marathons and training runs so far with these, but have had them since December. I prefer the MPow Cheetahs....especially because I don't worry about them getting wet or breaking cause they're cheaper to replace.