Which sport should I get into?

Now I've been one of the kind of people who like fighting sports. Some sports which I've found interesting were wrestling (both professional and amateur, very fun.), boxing, kickboxing, and some form of martial arts. I'm looking for an overall very fit sport, something not too expensive if possible and widely available. Anything with a ring or a circle or anything of that kind is a plus. I'd just like to see some people's opinions on this.