I usually don't collect slot cards but have been picking up the Palms slot cards. Not sure if this is a variety or not.
Card imprinted with Club Palms and the number is on opposite side of a regular issue card. If collectors consider this a variety then I have 7 different cards from the Palms. This one is passed out to customers and then the host enters their name and the system picks up the number to that name. No need for the customer to ever go to the Club Booth unless he loses his card or wants to cash in points.
The Nine Group, Rain, Ghost Bar, etc also has cards, but I have not seen them yet.