Are you talking about getting paid to answer surveys and complete offers? I wouldn't recommend any of those types of sites though. They are a waste of time IMHO. My personal preference for making money online is through the purchase and sale of domain names. I have registered and purchased several and will start selling some in the near future.
Another good solid way to make money online is buying cheap items on eBay and then selling them for more.
Do you work with web development at all? Google Adsense is a great way to make money online and anybody with HTML knowledge can do it.
Adsense is actually pay per click, so yes, it is profitable, but are you talking about where YOU get paid to click ads, etc? I have seen things around like that but that falls under the same category as the scams I mentioned in my last post.
What exactly are you looking for? Maybe if you posted some of your ideas it would be easier to help narrow down the ones that have a high success rate.