Harry Dance: webmaster tools is the one for you ;
Steven Ciccantelli: Tons of free ones that allow limited use and of course you can upgrade to the premium plans.Back link Watch is pretty good and allows some use of Ahrefs.
CalvinAyre.com: Most free backlinks analysis tools would only give partial results so it's recommended to use a combination of these tools. Check out ;Open Site Explorer, Backlink Watch, Ahrefs and MOZ. You can also download and install the free version of SEO Spyglass.
SEO Question :- Tools to check backlink without costing money?? 
