I have the Jawbone, Palatronics 925 and the Jabra BT530 in my rotation. Price to feature ratio, I would have to choose the BT530 over the others ($35-$45 on Amazon).
Like Dubdub said above, it comes down to preference, much like fashion and phones.
Think I'm going to go for the HS-500 as I prefer the look of that to the HS-655+, and what's the point of getting something if you're not that keen on it???! I'll keep you all posted on how I get on with my new headset, and whether it's any good. Fingers crossed!!
The reviews seem to say Plantronics Pro is the best if you don't mind huge/ugly, after that the Jawbone seems to get good marks but it also has a lot of pissed off customers from parts breakage and weird quality issues.