Skype is extremely user-friendly and easy to use! Simply sign up and add your contacts to speak, no servers needed whatsoever! You can hold large group conversations by simply clicking "add" its very simple, and free!
Downfall; Not good for use with games, Skype is a large program that may lead to lag spikes while in game.
In order to use Vent you must have a little more than basic knowledge about creating servers for talking (if you want privacy.) It is free to host a server of 8 people or less. If you wish to host the server you must download Client and Server downloads. If you are simply joining an already existing server you only need the Client download.
To create your own server download the Server, install completely. Command prompt will pop-up, Simply enter your Ip Address;
Downfall; Voice chat may lag for users far away from your server or a purchased one. Free servers only host 8 people at a time.
3. Xfire
This is absolutely the most common way users speak to one another in Crossfire. Simply download the program and add contacts. This is a great tool because it can be easily accessed while In-game! Includes very little lag and it's free!
Now this is again one of the most common Voice chat programs used by Gamers. Includes minimal lag and is extremely popular. you need just a little over basic knowledge to host your own server.