under NY state law would a negative review of my business be considered libel slander

This is an area my firm has been involved in quite a bit in the last few years as instances of "internet defamation" have escalated. The law strikes a balance somewhere between free speech and defamamtion. Although U.S. law affords ample room for criticism of companies on the Internet, free speech rights have limitations. Copyright, trademark, and defamation can interfere with a site's ability to say, "This company sucks." Defamation, the dissemination of false information that injures the reputation of another, marks the spot where speech becomes a cause of action. So when you say "unfairly" do you mean "untruthfully?" If you do, then it may be actionable. If it is just another person's opinion that is likely to be protected speech. Please feel free view my profile and to call my firm for a free consultation as we deal with these matters regularly and would be glad to give you some direction at no cost. Ourtoll free number is 1-800-640-2000