There are a few free tools, http://www.backlinkwatch.com (without the 's' as the above user put in) http://siteexplorer.search.yahoo.com/ Once you are at google.com, in the search bar type: link:http://www.example.com
I check site:yoursite.com and modifying the preferences. Also I like to check Alexa for pages linking in.
If you are looking for free methods backlinkwatch and yahoo site explorer. For paid, I would use Market Samurai's anchor text analysis.
Hi friend, Google webmaster tool is the best for back link checking. and you can also use Google analytic for back link checking site. this both are the best site for back link checking site.
Hi D79312, I noticed that you're listing an SEO/SEM company in your sig. I was wondering if you have any recommendations on paid tools? Have you tried out SEOMoz's tools before? I've always been interested in trying some out but I'm sort of stuck in the 'there-are-just-too-many' conundrum.