Does the media in America have a liberal or conservative bias?

Question From User - Answers in Comments.

I was at a social function the other day and overheard some very interesting conversations. In one corner of the room there were people complaining about how the media is so liberal and in the same room, another group was talking about the conservative bias in our mainstream media. What do you guys think and why?
Just wanted everyone to know that I really appreciate the answers given. Many of you made good points and were very nice about it for the most part. I will have a very hard time picking the best answer since so many of you deserve the points.