I'm still chuckling.
It's a pretty packed show, preserving -- and expanding upon -- quite a lot of the bits from the original mind-melting film (which was my first serious exposure to Monty Python, though my very first exposure was a TV clip on how they blew up Mr. Creosote in The Meaning of Life; I saw that when I was 10!). It also makes copious fun of Broadway shows, and I got a surprisingly large number of those jokes, too (surprising because I'm not too experienced with Broadway shows). And and it's tuneful; Eric Idle and John DuPrez (it's pronounced "Doo-Pray," which I didn't know until now; I'd thought it was "Doo-Prezz") piled on song after song, even giving one song to dead people. It's Broadway! You can't stop the singing!
This production's King Arthur is wonderfully weary and put-upon, though at least he has the Lady of the Lake actually appear in this version of the story to back him up at key points. Dennis (or, as Spamalot conveniently renames him, Dennis Galahad, thus making two characters into one) may still say "You can't expect to wield supreme executive power just 'cause some watery tart threw a sword at you!," but at least he then sees her and sees that she's no watery tart. And there's sex appeal (dancing! a wedding! another wedding!), and an ending that's almost literally pulled out of someone's ass, which is just a beautiful way to do it: it's a little perverse, like the film, but with more of an actual resolution. Heh.
Finally, speaking of sex appeal, my fellow sick bastards will be happy that Spamalot features an unspoken cameo by the virgins of Castle Anthrax (to quote the film, "We are but eight-score young blondes and brunettes, all between the ages of 16 and 19-and-a-half, cut off in this castle with no one to protect us. Oh, it is a lonely life: bathing, dressing, undressing, making exciting underwear..."). Again, unspoken, but there.