I myself use phpAdsNew but wanted to get some insight and see if anybody has any other ideas in case I decide to change or whatever if anybody knows of a more percuiliar software that is reliable as phpAdsNew.
I use phpAdsNew and am currently testing M3 (Max Media Manager) which is basically PhpAdsNew v3 - so some good features although it isn't as stable as yet.
RMX-Direct from Right Media is a pretty good hosted free solution though. I'm getting started with that and finding it pretty intuitive and being hosted is always a bonus.
^^ I agree with csmaster, although M3 sounds very good I'll have to check it... but on the whole topic of remote hosted, I give a thumbs down (because if their server goes down, your banners are with it.)