Yesterday, I was introduced to Raidcalll wich is fairly similar to Teamspeak and Ventrilo but it has a better interface. The servers are free so you can make up to 3 Servers with your account and have 50 people online at a time. It's completely free and it has an in game interface for any game. I fint it much better than vent or teamspeak, but that is me. You guys should give it a try, it's amazing!
I'm really not sure if it's new or if it's been around for a while.
I recommend something simple like Vent or TS, but with better quality and stuff. So I prefer Mumble. Mumble is an open source, low-latency, high quality voice chat software. It does really have a high sound quality (seriously, it sounds like you're next to the guy, and it's really sensitive to voice). I think not a lot of people know about this, but it's really cool, you should try it. Here's some info.