I've seen a few of these before. But what I am looking for is the best available based on real use (not supposed use or "I heard" use). And real world tests based on quality, features, and stability.
Links to programs listed in the poll.
https://axon.dolby.com/
http://www.teamspeak3.com/
http://sourceforge.net/projects/mumble/
http://www.ventrilo.com/
http://www.skype.com/en/
http://www.raidcall.com/v7/index.html
Please be detailed in your responses.