I generally use Facebook to speak with friends and family, it does the job well. I want to make a Google+ account as it is the 'new thing' at the moment, but I can't because there's an age requirement?
I don't really use any, Harris Google + has an age requirement because they are testing it still (Beta) but when its fully released there won't be an age restriction.
I only used Facebook for socializing but ever since the admin changed much of the Facebook appearance,I am starting to have a little issue with it.Especially the chatbox.Can't really see who is online.Instead,both the online and offline contacts appear which I find it really kind of pointless to show the offline contacts...
It is still Facebook for me. I am not that familiar with the other social networking sites. Also, I find Facebook easy to use. But I know that the others also have their strong points.