i put cpalead. but really for facebook ads their are tons of good ones depending on what your app does
RockYou is a pretty solid network to work with, check some of earnings stats from a single application here: Facebook Application Banner Ad Earnings Stats They're all fairly decent, you can earn money from any of them if you have good ad placement within your application. One tip I will leave you with is this... Check out a network's text ads first, the aesthetics. If they don't look attractive, like something you'd be willing to click on yourself, then chances are good that your users won't click on them either.
Both RockYou and CPALead are great for facebook apps. CPALeads virtual currency option is ideal in my opinion.
There are plenty of great networks out there that can recommend top offers for social traffic. I'm an AM at Affiliate.com & would love to help out anyone needing facebook or twitter offers or any social networks at that. We have a great variety and Top payouts, so PM if you'd like me to help recommend a few. Good luck~