I currently use the Plantronics Supra H51 headset at work with my Avaya phone, and it is such a help! I love being able to type with both hands while I do work on my computer. I could not survive holding the phone receiver between my ear and shoulder while tilting my neck and trying to see the monitor.
This headset has a great sound quality. I work in a noisy environment, but I can hear the other end of the call perfectly. The band is lightweight so it doesn't weight down on my head and neck, and the padding on the ear is comfortable and I can tolerate during those long phone meetings. The microphone has good quality, as every can hear me clearly when I speak. The length of the microphone is long and is in front of my mouth, so this makes me really feel like the other party can hear me. I've had other headsets that end near my jaw, and I always feel like they can't hear what I'm saying, so this is a must have for me.
My headset has a quick-disconnect adapter, so you will need something to hook it into your phone. Since my avaya phone has an rj-11 port, I had to buy a quick-disconnect to rj-11 adapter so that it is compatible with my phone.
Overall, this is a great headset. You can usually find it pretty cheap, and it is a great value for the price