Oh that's easy. Google Hangouts. It's free. My grad school group met a couple times each week on Google Hangouts video chat. We could see and hear each other.

I use it with my friends who live abroad. We used to video chat more frequently in the past -- not a lot lately -- but it was fun to see each other while we chatted. Like, when I lived in Chicago, I met my close friends who were there studying with their respective teachers in opera and concert piano.

Free video chat is available if you have a computer or smartphone with internet access.