My wife and I went to see Spamalot last night in Boston. It is very funny, and I do recommend it if you like Monty Python type humor.
The storyline was about 80% The Holy Grail and 20% new material, but it was done thoroughly tongue-in-cheek. There was a very good scene, and song, about how a play can't make it to Broadway without a Jew in the crew. Really, it was all in fun.
Go see it. It is a touring show, so it might be near your city this year.