Of top of my head, there are 9 brands in the bag right now, although most of my throws are MVP (Envy/Hex) and Innova (Teebird/Shryke, Corvette FH). We'll see if the Bohrium makes the bag when I get mine, that would nudge it to 10. Bohrium would need to be an improvement on Shryke/Corvette (BH/FH&BH). I'm anxious to find out.
I'm tempted to see if Explorer > Teebird, but my Teebirds have been quite reliable so why stir the pot?
Kast (Berg) - MVP (Envy, Hex, Paradox) - RDG (Stego) -Discmania (Tactic, MD3, old PD, Essence) -Westside (Stag, Boatman, Tursas) - Innova (Teebird, Corvette, Shryke, Invictus) - Prodigy (FX2) - Discraft (Nuke) - Millenium (Draco)
There's overlap (e.g., MD3 and Hex, PD and FX2, Nuke and Corvette, heck even Boatman and Teebird compete).
Some of these slots are extended experiments (Paradox, Stag, MD3, Tactic, Nuke, FX2, old PD). The rest are established.