These are the type of affiliates that I like best. When someone buys, say a new basic web hosting account, it should cost them $50-$100. These companies pay you $50-$100 if you refer the customer. How does that happen, well they pay you for the lifetime value of the customer, not just for the original sale. As all of you know, the cheaper the product, the easier it is to close.
Hosting companies with affiliate programs would be Hostgator, Bluehost and GoDaddy. Be warned though, this is one competitive niche.
You will find similar subscription type sellers on every affiliate network.
RegNow specializes in software sales. I include their program here, because it demonstrates an important concept, the 30 days free trial. Buyers download and use the software and use it free for 30 days. Then if they buy you get your 30-50% commission.
Netflix let's customers subscribe to a downloadable video and DVD by mail service. They pay $16 per free 30 day trial subscriber, that you send them. Netflix operate in the USA and UK. The affiliate program is difficult to join, I think they currently want to see a niche specific site.
They pay 40-45% on magazine subscriptions. There is a magazine for almost every niche. Because of the relatively low cost of subscriptions you get a lot of impulse buys with magazines.
Insurance is a another great niche. A good example would be DentalPlans.com they pay $47 per sale through ShareASale's network. But there are many great insurance programs that you can join.
One big ticket item, many people spend on every year is their vacations. Orbitz pay 2.5% on packages, $3 on air tickets, $25 on cruises, 3-5% on hotels and $4 on car rentals.
It might not seem like much but holiday costs stack up quickly. Book a holiday for say a family of 4, think about the tickets, hotel costs and car rental. Your commission can get up to $100 very quickly.
Naturally if you look around you might get higher commissions from less reputable vacation planners, but the bigger ones convert better.