Poker Perfection!
I've played a few gambling games on NG and other places, and I have to say this is hand down the best.
The players all have realistic personalities - a lot of poker games fall into the trap of making players with extreme personalities, e.g. they always bluff, or they never bluff, but in this game the players have balanced and realistic personalities. The graphics are very good too, I like the top-down viw of the game. It's incredibly long - almost too long in fact.
The only probems are that it can get quite slow - either becuase of the high quality graphics or because of the AI taking it's time - maybe an option to turn graphical quality down would help this? Also, the players arms, especially the women's, look a bit disfigured. This wouldn't matter in a cartoony 2D game, but in 3D it looks wierd - the hands are huge but the arms are like twigs.
The only suggestion to inprove, apart from the ones above, would be to add more variety. Playing the same game over and over can get quite boring, maybe add different types of poker (e.g. 5 card, 7 card etc.) or maybe different card games such as pontoon (blackjack in Americerish), or bridge? Maybe even have games like roulette, although slots obviously wouldn't fit in with the wild west theme.
But, nonetheless, this is an amazing game. Bravo!