There just too many people got banned from Adsense program, and majority of these people may not commit to fraud case (example victim of clicks bomb by other visitor). Some of the people are just not able to got their Adsense application approved, because of the tighten policies or some unknown reasons.

I had the same problem before, as my application was not accepted despite trying for countless time. I decided to share my homework done by myself to source for alternative programs that similar to Adsense during the period here.

Here are the example sites like Adsense, that’s worth to try (I only list some that familiar with)

a) Infolinks
This is in text advertising, if you see in some blog and websites; whenever you point you mouse cursor to the underline text. A small box will pop up displaying the ads, you got rewarded if people click on it. Also, you can use Adsense with Infolinks to maximize your site income.
The rewards are slightly higher compared to the in text advertising companies around, not to mention the easy approval.

b) Adbrite
This is the second popular ad network after Adsense. Adbrite allows you to manage the ads to be displayed on your site. You need a Top Level Domain (TLD) in order to publish or participate, but you may check again with them to confirm.

c) Yahoo! Publisher Network
Similar to Adsense, and easier for US citizens when come to the application
The above 3 ads network worth to try for those having difficulty with Adsense, and always check the details before signing up!! 

Anyone publishing using the above please leaves your reviews/comments to help the rest