I've found 60 different that were issued by Nevada casinos. Remember there were $20 denominated roulettes at MGM and Paris. Even the old California Club Las Vegas card room had a 20. In Reno, the Palace Club and Doll House had 20's; I doubt very much that either of these had baccarat so they must have been card room chips too. Harolds Club had at least 5 different. TCR shows 162 just for Nevada!

It's an interesting category to collect and not many new ones being issued.