If you really want to know my favorite then I would certainly name Pinterest. I get such a joy when i see a beautiful picture because I know Pinterst is going to spread my love to many.
My favorite social network is facebook, however i also like google plus. On social networking site if becoming very difficult to find out a friend through search as there open several fake IDs on it. Fake IDs should be deleted.
My favorite and what I consider to be the best social network is Facebook. Looking at what the company has been able to do, I think the company will become a mini Google. Actually, it's already that. Great job Mark Z.!