For wired, my recommendation is the Ety-Com. I think you can get one for ~$35.

http://www.etymotic.com/ephp/er22.aspx

Positives: Excellent noise rejection with the microphone. In-ear design for the earpiece means that you can hear the other party no matter how loud the environment is.

Negatives: In-ear earpiece may not be comfortable for some (think Shure in-ear canalphones). Microphone placement is important, and there is a narrow range where it works well (which is why it isolates so well).