Speaking from my RadioShack work experience, most people find Plantronics to be the most comfortable and they usually have the best sound quality for the price. I'll give ya a quick breakdown:
Plantronics: Very comfy, good sound quality, cheap!
Motorola: Usually uncomfortable, poor sound quality, good range though
Samsung: Stylish, decent sound quality
Jawbone: Everyone I've talked to either says they LOVE it, or they HATE it. I'm more inclined to go towards HATE because a lot of people just listen to the hype about them and think they must be the greatest in the world
LG: Haven't played around with them enough to know