Deadwood, SD. I liked the old west history of all the saloons. There are some great national and state parks nearby, as well. South Dakota legalized gambling in Deadwood as a means of paying for restoring the historic downtown, but to keep out Las Vegas style casinos, they set the max bet at $5.00 for all table games. They recently raised the max bet to $100, but I understand that it's still a low rolling kind of place.
They had plenty of blackjack and poker tables when I was there. I don't play slots, so I don't know what the video poker is like.