Is It a Bad Idea to Hang Out With Co-workers Socially? [POLL]

I like my co-workers and I have to admit that I know some of them better than I know my closest friends just because I spend a lot of time with them. Although, I have learned over the years that it can be a bad idea to hang out with co-workers socially. On the other hand some of my old co-workers are truly my best friends. So which way is the right way...to hang out or not to hang out?