SMH-5 by Sena
The one thing that really makes the Sena standout is the intuitive dial/button. Something that's easy to operate while riding and with your gloves on.
Update 4/12/12: I just found out that these aren't available from the distributor just yet. They should be available for shipping in May / early June. Can't wait to get my hands on these!
This is on my wish list, because it's a smaller, more compact version of the popular SMH-10. The difference between the SMH-5 is that it only allows for rider 2 rider communication, so only 2 people. The SMH-10 will allow you to connect up to 4 total riders, after a firmware upgrade. The price point is also nice at $129 for one or $249 for two!
Previously, with the SMH-10 you had to buy the pair. Now you can ride solo with the freedom of no one else talking to you, unless they call you first. :)
The SMH-5 is on my hitlist to replace my aging BlueAnt headset from way back.