Wow, that's a toughie as snuffs seem even more individualistic than pipe tobacco. A line that I've been meaning to explore is Rosinski. I've heard quite good things about it. I have come to understand that ordering direct beats Mr. Snuff.
I presume you've tried white snuff; Dholakia White, White Elephant, Cheetah. Very strong, very hard to take, very satisfying.
Everything from Toque is good if you like the grind of their flour. A couple sleepers that you may not have tried; USA citrus, Pomegranate, Grapefruit, and Apricot. My favorites from the line. Also, Roderick is about to unveil a brand new line, so that should be spectacular.
Not a fan of most of the lakeland company's snuffs although SG does make Viking of which I quite like Dark and Thor's Hammer. Apparently they're copies of a couple things in the SG line, but I don't keep up with the snuff world the way I used to. I'm guessing/hoping you've had F&T High Dry Toast? It's one of my favorite plain snuffs.
If you don't like Schmalzler's stay far, far away from South African snuffs as they make the German stuff look like a fine grind.
And now that Daniel Richard is gone and Jaap Bess no longer makes snuff at the mills, the snuff world has many fewer shining stars, so if you like something stock up, they seem to be going away much faster than pipe tobacco. I'll ramble more if I remember more to ramble about.