We saw Spamalot Last night. It was a regional production, so no Tim Curry or David Hyde Pierce, but it was a great show none the less. Gary Beach was King Arthur, and he did an excellent job.
If you ever get a chance to see a professional theater company perform Spamalot, do it.
I promise you wont regret it. Not only will the wife get a night out, watching Spamalot gives you a +3 to your Geek Cred.