My Grandmother gave me several bottles of old 'Salon Selectives' conditioner. I know they are old because they are in different bottles than they are now. They still smell fine, but I was wondering does conditioner go bad? The only reason I have considered using them is because there are no cones.  Any ideas?

Most commercial products have a very long shelf life.  They may experience some separation, but they don't really go "bad".  You could open them and see if there is a clear liquid on top.  If so, there has been separation.  You could try to remix the product and give it a try.  I don't think it would hurt your hair, however, it might not give the same results as a newer product.