Commission junction (cj) brings alot of people alot of money ive made a few hundred pounds (gbp) with these
Click bank - iv just started using click bank so dont really know that much about them
Webgains is a good affiliate program and they pay weekly
i also use ourfreestuff.net and have made a few hundred dollars over the last 6or7 months
you have to find the right niche but if you do you can make loads
if you think about what your blogs are about by looking through the various programs (especially in CJ) you can find some links or banners and add them to existing blogs and mentize them even more.
thats what im in the process of doings. leaving landing ages filled with affilaite links to having one or two quality blogs with targeting affilaite programs incorporated in to them