They are pretty good. But it's hard to say they are the best, because it depends on your niche, traffic sources and offers, etc. I'd say neverblue, ewa network and peerfly for me.
CB can be awesome in the right niche, but most of the products being released these days are crap. That makes their return rate the highest in the industry. I tend to work with Google Affiliate Network, CJ and Prosperent. You can still make a killing with CB if you get the right product, and the best I have seen in years released yesterday.
So you guys earn with prosperent.. I always got error in login like wrong password.. i have requested password reset twice already since account creation last June 2 and now my ads are gone along with my impression...
ClickBank can be ok if you can find the good products, most of them are just garbage now a days with a high return rate. It can be hard to rummage through to find the good ones. I like to use Commission Junction, Share-A-Sale, Paydotcom as well as a couple of others.
Clickbank sucks. I make money more with paydotcom. There's also rumor that they shave their affiliate
Clickbank is pretty good, I have made money with them and explain how in my ebook in my sig. I use multiple resources to make money because you don't put all your eggs in one basket.
It all depends on your relationship with your affiliate manager, some CPA can give you customised rates