I prefer to have a boss who is collaborative, transparent, honest, and trustworthy. It's a great bonus if we can connect on a more personal, social level, but not a "must have." I appreciate being treated not necessarily as an equal, but not as an inferior.
Great bosses treat reports with respect, act as an advocate for you, and build your credibility in the organization.
On the other hand, I think it is bad form for a boss to take credit for work you did. The best bosses understand that they don't have to piggyback on your successes, because if their employees are successful, in turn, they are successful! No ego required.
What are some of the traits you look for, or avoid, in a potential boss?