There are many good clickbank products, if you are talking about affiliate marketing products then there are many great products that I have read.If I could name few, I would recommend, ewen chia's products, cody moya's products and Mike Filsaime's products.There are many more but usually I find good information from successful and famous marketers. added: and I always learn something from them.
I like to make my 1st affiliate sale from clickbank - its been over a month with over 400 referals, but nothing yet once i make a sale, I might connsider PPC!!!