I'll vote for OpenAds or whatever it is now... OpenX. I started using it a year ago and it works really well. I too found it a bit much to get to use at first because all I really need is an ad server that keeps stats as well. It has a nice feature that emails statistic reports to your advertisers which is sweeeet! It does a lot more too and since it is free you can't lose for trying it. If a knuckle dragger like me can figure it out then it can't be too difficult to use!
