Google Webmaster Tools has a backlink checker by default.
Register an account, and add your website and verify it. (If you haven't already)
After that, go to the menu on the left, Traffic -> Links to Your Site:
Hey guys y[FONT=Verdana, Arial, Tahoma, Calibri, Geneva, sans-serif]ou can check your back-links from opensiteexplorer.org, majesticseo, GWMT etc. I know these 3 are the best tools to watch back-links.[/FONT]
Ahrefs are really expensive and if you need any other back linking tool which you want at an affordable and at really inexpensive cost then you might probably check out free seo tools