Should the best car tire go in the front or back?

I took my car in to American tires to get the front two tires changed (95 camry v6). They told me that they were gonna switch my back tires to the front and the brand new tires to the back as a safety precaution because the best tires should go on the back. I thought that the best tires should always go in the front? A friend of mine also said that the best tires should go in the front and told me that it sounded like they were just trying to get my other two tires popped.