I think the question really depends on what type of traffic method you will utilize towards your affiliate products and offers. Also which type of affiliate products and offers you will promote. I use Neverblue and MaxBounty for the CPA(Cost Per Action) offers and e-mail/zip submit offers, when I promote different type of affiliate products for sale, I use RapBank, which are a company established by affiliates for affiliates. The reason I choose RapBank is their instant commission payout plan, which are awesome if you use Pay Per Click advertising, then you can re-invest your earnings into more traffic and then again more earnings, until you reach your desired income goal pr. month.
I avoid Clickbank, as it is to easy for people to get a refund after the sale has been done.