Like google, yahoo, msn, amazon, facebook, myads, looksmart, advertise, AdBrite, BuySellAds, AdMob etc.
What kind of reviews that you want ? Admob is for mobile btw like MobGold, Mojiva, etc , and other are similar but Facebook for social networking.
According to your online advertisement experiences, what can drive useful traffic and what can't? What are good and what are rubbish?
what do you mean by 'useful traffic'??? most ad network allow you to target your desired audiences... from my experience the likes of buzzcity, mobgold has this feature that will help you manage where your ad will appear...
Although some advertisement system claim how it helps you, how it works! I do afraid of its quality of traffic I buy. No matter how the situation, I think these are few of ads systems that are worth inverting. Google is worth. And yahoo? amazon? ebay? or others?
Google, Yahoo, man, Bidvertiser and Adbrite are the best advertising networks and you can trust them.