My new favorite plugin for a social network is Ultimate Member. It looks beautiful out of the box, and offers a complete suite of add-ons that covers really a lot of options: notifications, private messaging, social activity feeds, social login etc. During some projects I’ve worked on I’ve created some widgets that I needed for those projects. The New Members plugin lets you show the most recent members on your site, while the Most Visited Members plugin adds a widget with which you can show which users have the most visitors on their profile.
There are also third party plugins that can add Google Maps functionalitity to your members directory.
For developers, it is great to build upon. A lot of thought has gone into the extendability of this plugin.
In my opinion, you should grab the complete package of add-ons, it is just to much value for money to leave it.