I think Bidvertiser is the best alternative for adsense. Other alternatives are Chitika, Kontera, YPN, Adbrite and so on.
I've been testing several different ad-networks for the last few weeks and for ME, on my site, Kontera was the best (actually outperformed Adsense for the last month). After Kontera was Chitika Premium & YPn. Adbrite was 2nd worst - Bidvertiser was THE worst. Your results will vary - but it's best to test everything yourself to see what works best on your site(s).
I will say if you are in Usa than go for ypn . Than you can try adbrite and than bidvertiser . In bidvertiser you can approve ads manually .