Yeah, I don't use just one. I use several. Sometimes You can search your topic and click through other sites and find affiliates or cpa offers that way also. Seems like good ones are dateing, finance, insurance. Another good thing is to find a good niche high in demand with limited compitition, then find a good offer in that niche.
Like if your site sells bibles then the adult dating industry wouldn't be a good match for your site.