Recommendation for a good banner rotation program

Hi, Can anyone recommend a good banner ad rotation program....there are so many when you google....I assume you get what you pay for...so I'm thinking I should buy one instead of the free ones. I need it to also track and record click data. Thanks -Chip
PS, I like the sounds of this one by "ad server solutions" below but it's the most expensive...like $600 or so expensive!
https://secure.adserversolutions.com/adserverorder.html

I have been using the free phpadsnew for a while and it does the job.

Seems to have been baught and renamed, but I think it's still free: http://www.openx.org/ad-server