Manu Cornet of the Ubuntu team has created a simple yet effective site called Why Linux is better which I thought was pretty good.
Microsoft spend million$ on their "Get the facts" campaign where they get "independent" companies (affiliated with Microsoft if you read the fine print) to say that Windows is better than Linux. Sure enough, there are some points where Windows is better but far more where Linux is better than Windows. Anyway, this is what Manu is up against and still his delivery is much better than the Get the facts campaign. All he has to do is to be honest.
Keep up the good work Manu!