I think you can already include instagram since it includes socialization. This is by far the best and my favorite.
I don't really like any social networking site because of what they stand for, but if I had to choose I would pick FaceBook.
Facebook is my favorite social friendship site as it is very popular in my country and all my friends are active on this site.
my favorite social media network is facebook.now i can not think without facebook.i have to spend at least 2 hours in facebook.i share my current status,photos,videos,jokes with my friend.