A thing I learned at the dentist yesterday: Scope mouthwash has virtually no helpful active ingredients; it's just minty water. But it's such a well-known brand that people buy it by habit. For good dental health, we should be using Listerine Total Care or Crest Complete mouthwash.
I feel like the word needs to be spread, so we can get out from under the spell of marketing, and learn what products are actually useful. This page has some good info, and mentions the Listerine product specifically:
Edited to add this line from that dentalcarematters page: "What is the best whitening mouthwash? – There isn't one! NO rinse is able to really improve the shade of your teeth." Once again, we have to battle against marketing!!