I think Valvoline wants for people to think they are a special brand. In their advertising they say that they are the choice of more mechanics than any other oil. This may actually be true. I have met a lot of mechanics and a lot of them do recommend Valvoline. This shows the power of advertising.
Amsoil could certainly be considered more of a special oil than Valvoline. Redline could also be considered a special oil.
I have used Valvoline. It is probably about the same as any other motor oil that meets requirements. For a conventional motor oil I prefer Chevron. And I like a synthetic motor oil in the wintertime and I usually use Mobil 1.