Today search engine optimization greatly depends on quality of inbound links to increase your serp rank and ultimately increase affiliate or ppc adsense,ypn.
Personally, I use Ahrefs, Open Site Explorer and Backlink Watch. So far, I get what I need in using these 3. But I have to say that I have to give.
Backlink Watch, Backlink Checker Link Building strategies Tool Will Find Quality Backlinks To Help Your Site. Is there a version of Google that excludes backlinks as a ranking factor?