I have profiles on three different social network, I am so active on Friendster because most of my friend are on it. I have accounts on Myspace and Facebook not so on it until recently that most of my husband's side are on it.
Some of my friends are switching for good to Facebook and leaving Friendsters behind for ever, hhmmm, It made me think now, but each of this social networks has their own features that I like so my two top choice are the F's, Friendster and Facebook.