I use the plantronics 510. It is a little old school in that it is not a fashion statement, though I think audio in and out is excellent and the battery lasts forever (huge plus for me). I primarily just keep it in the car for when I am driving, so the less I need to remember to bring it into the house to charge and then back out the better.
EDIT: Plus you can get it on Amazon for <$40. At this price I don't feel bad if I lose it or wash it.