BLOODY fantastic. Gorgeously silly. Superlative and better. "Monty Python's Spamalot," dazzlingly staged by Mike Nichols, opened last night at the Shubert Theatre, where it will hereafter delight lovers of Python's immortal Flying Circus, devotees of Spam and even those who've never heard of either.

The bizarre, merry lunacy of Monty Python, with its curiously British yet marvelously exportable sensibility, must be a difficult thing to bottle for Broadway consumption. How funny are coconuts economically doubling for horses - or a killer rabbit executing his rabid mayhem - for those who aren't yet aficionados?

Fortunately, "Spamalot" - described with telling accuracy as "lovingly ripped off from the motion picture 'Monty Python and the Holy Grail'" (accent on the ripped), offers virtually non-stop jokes.

Only the very dead could hold back their laughter, and even they would probably rattle a few appreciative bones.

Former Python Eric Idle wrote the lyrics and book, and assisted Python composer John Du Prez with the music.

Together they prove what Mel Brooks postulated with "The Producers": Anyone with a sense of the ridiculous - and nostalgia - can write a Broadway musical.

The story, ostensibly about King Arthur and the search for some Holy Grail, is really about silliness and Broadway, and rife with Idle's wonderfully absurdist exchanges:

"Where are we going to find a shrubbery?"

"Well, maybe we can build one? Out of cats."

"Don't be ridiculous. Where are we going to find cats?"

Sam Beckett would have been proud of that.

As for Idle's lyrics - well, Noel Coward and Cole Porter might have produced a gems such as "There's a very small percentile/Who enjoys a dancing gentile."

That last is part of a show-stopper by David Hyde Pierce's elegant, poker-faced Sir Robin, who points out: "We won't succeed on Broadway if we don't have any Jews!"

The show itself is a sweetly wilted bouquet to the Great White Way, a heavy-handed but light-fingered pastiche with a deliciously pompous Christopher Sieber as a popinjay Sir Galahad taking the mock out of Sir Andrew Lloyd Webber, Bernstein and Sondheim, as well as Boublil and Schonberg, the makers of "Les Miz."

The nuttily funny Hank Azaria, who clearly has a ball playing the nasty French Taunter, is also Sir Lancelot the (closeted) gay knight (if you have to have Jews for Broadway, you also have to have a few gays), complete with a Peter Allen routine.

These Knights to Remember - and the wenches they brought with them - make up a Round Table of supreme excellence.

At its head, Tim Curry, his indomitably jolly face registering a sunset range of long-suffering concern, makes a great King Arthur whose reign has come.

Steve Rosen and Christian Borle glitter in a variety of roles, and Michael McGrath, playing his coconuts with virtuoso skill, proves cheerfully woebegone as Arthur's sidekick, Patsy.

Then there is the surprise hit of the show: Sara Ramirez, who sings like a trouper and keeps dazzlingly afloat as the Lady of the Lake.

They've all been royally treated by Nichols, who stages the glorious shebang with a daring spontaneity, as if he were making the entire thing up as he went along. He has "Spamelot" working with a glossy grandeur, without a single fall from comic grace.

He's helped by the boisterous choreography of newcomer Casey Nicholaw, Tim Hatley's crazily imaginative and brilliant sets and costumes, Hugh Vanstone's particularly illuminating lighting and an altogether perfect cast.

This is one of those Broadway shows of shows. Steal a ticket, even if you have to get a killer rabbit to help.