Caribbean stud poker is a great way to be introduced to the game of poker. Although not as popular as blackjack and roulette, it's a great third or fourth choice. The game is played on a blackjack sized casino table (a 'half moon' table measuring 6ft x 4ft) and is a mixture of luck and skill.
If your guests are keen poker players, and are familiar with the the different types of hands involved in the game, then this a great alternative to Texas Hold'em poker. Each hand is played against the dealer (not against other players) and can be played in under a minute so your guests are free to leave whenever they choose.