The only grand win I ever saw personally the fellow was betting $8 and hitting the button like a crazy person.
I've gotten the game specific progressives a few times but never the grand. At one casino I saw a gal winning over $20K on the super games on the Buffalo Gold at a $4 something bet. There could be others - those are just the ones I can think of. Another has Buffalo Gold, Pelican Pete, Miss Kitty something and Timberwolf Deluxe.
One has Wicked Winnings 2, Buffalo Deluxe, Wild Panda and I forget the other one. There's a couple different ones of these.