We've been using Slack, which seems like maybe it's a cross between Team & chat. And I can't imagine life without it. So useful. I get close to zero emails from anyone I work with.
I can't recommend Slack more. It has an amazing web-app, works perfectly and the basic plan has no limit on users. I've tried both HipChat and Campfire, and I always felt that they were never the primary focus of the companies that own them.