Best show in Las Vegas right now. Seriously, seriously funny - you'll have tears in your eyes. Unfortunately, it is closing on 7/13/2008, so if you are coming to Las Vegas before that date make sure to fit Spamalot into your schedule.
John O'Hurley is magnificent in the role of King Arthur, and looks and sounds like he could have stepped right out of the film Monty Python and the Holy Grail. The show has been updated with Vegas-specific and politically timely humor, so even people who tend to dislike Monty Python will find more than a few laughs waiting for them.