Adengage is one. They pay ok but only have certain types of ads and sites. Clicksor is another but pay less than adengage. Adbrite some say they make good money i never did and they have certain sites that do well. Yahoo is another one but they are same as adsense in terms of rules and sites. A good affiliate link or program might make more money. If you find right one for topic of your site you can make good money.
Bidvertiser: $10 minimum payment via paypal. Very tedious to use, you need a unique code for each page you place in your site.. ad formats are okay, very similar to adsense. Tends to show irrelevant ads, gambling, casino mainly.
there are so many adsense alternatives thread on dp . i have collected some them. here are the adsense alternatives from dp http://forums.digitalpoint.com/showthread.php?t=327876 http://forums.digitalpoint.com/showthread.php?t=328880 http://forums.digitalpoint.com/showthread.php?t=48368 http://forums.digitalpoint.com/showthread.php?t=157386 http://forums.digitalpoint.com/showthread.php?t=187662 http://forums.digitalpoint.com/showthread.php?t=237325 http://forums.digitalpoint.com/showthread.php?t=302278