facebook and twitter but you can also consider the tumblr because its getting famous. seocentralservices
I have heard of Facebook but not dailyflak. I visited it and it seems like a standard Vanilla forum even with the standard theme. On top of the boring theme, there is a terrible logo. I don't see how this is anywhere near a social networking site, let alone the "best" social networking site. Perhaps you are shamelessly promoting it in all your posts because it is yours???
I think the site design is great, even if it is a vanilla forum software, it doesnt really make a difference for its use really. What I really like about it is that it is a journal sharing website. Which is more interesting to me than just chatting with friends on facebook.
It depends... if you are a B2B company, LinkedIn is the best, if you are a B2C company Facebook is the right social network for you Twitter works with both markets ... creating special event (with hashtags) or just daily interactions