Skype

This is a program that has gained a lot of popularity but surprisingly many people still don't know about it. Skype is the best video chat program and it's free. It's easy to use, just make an account, sign in, then add your friends. You'll obviously need a microphone and camera to use this effectively, I'd recommend one that has them both built in to make things easier. Here is a link to the page to download Skype.