Best Advertising "Ad" Plugin?

I was hoping someone could recommend a simple, easy to use Advertising or “Ad” Plugin. I am currently trying to get Simple Ad Manager to work on my blog, but it won’t save any Ad Places or Zones that I create. I’m not sure what I am doing wrong, but obviously it’s something…..is there a better Plugin that I could be using that is simple to use?

Thank you for any help that you can provide!!