Refinish Products - How many brands out there?
The answer is potentially exhaustive.
Especially when you start looking just within a given company, like some have pointed out...PPG has the Global line, the Deltron line, Vibrance, Shopline, Omni, and a bunch of others. And some variations within the line, like DBC and DBU bases inside Deltron with the coverage of the Concept clears: DCU 2002, 2010, just to name a few within a line of like 20 clears on the market just in the DCU line depending on what you're looking for. And all that's in just PPG. Now add all in the lines from Dupont, BASF...wow, the number boggles the mind.
And I think in your original post you asked about fillers and primers, too? USC, Evercoat, the old Bondo, and the lines of products coming out of those companies? WOW!