I might seem an unlikely member of the Church of Satan. I'm a hard polytheist who identifies as a cultural Catholic: most public CoS members are strong atheists and loud, proud blasphemers. But I nonetheless am a 2nd Degree member and a good friend of several leading Satanists, including High Priest Peter Gilmore. (Sorry, I don't know Marilyn Manson or Sammy Davis Jr.).
My reasoning is simple: I enjoyed the hell out of Anton LaVey's The Satanic Bible. It's a masterpiece of comedy by a great American curmudgeon - and like any good comedy, it contains plenty of serious truth beneath the laughs. People make the mistake of comparing LaVey to Aleister Crowley: his writing is much more in the spirit of Mark Twain, Ambrose Bierce and H.L. Mencken. And the fact that many of his followers and critics don't get the joke only adds to the humor. (Some people have accused him of plagiarizing Nietzsche, Jack London, and Ayn Rand. I'd only ask this: until Anton LaVey, who discerned the common strains of thought between a militant aristocratic elitist, a militant socialist and a militant libertarian?)
Many people have criticized the Church of Satan as an "Anton LaVey fan club." For me, that's one of its strong points. A fan club is a mutual appreciation society for people who enjoy the work of a particular artist, a place where folks with a common interest can network. Fan clubs don't seek to convert the world or put fatwas out on heretics who dare to defame their idols. Those who kill in the name of their favorite band or actress are treated as obsessed criminals, not feted as heroes and martyrs. Fan clubs celebrate the genius of talented individuals: they don't deify them.
I don't really care whether or not LaVey actually schtupped Marilyn Monroe or tamed lions in the circus. Given that he listed Basil Zaharoff and P.T. Barnum as major influences in his authorized biography, I would expect that he never let the facts get in the way of an entertaining story. Since one of his biggest messages was "there are no gurus," I'm not surprised to discover he didn't behave like a sainted guru. Nor do I care: my enjoyment of his work has little to do with his life. (Although I do admire his lifelong performance art piece: Howard Stanton Levy's creation of Anton Szandor LaVey is a brilliant achievement).
Do I worship Satan? If you mean the "Father of Lies and all that is evil in the world," obviously not. A moral worldview based on "I will be evil and do evil" may make for entertaining Hammer films or Marvel supervillains, but it isn't really very practical. But I do have a great admiration for the Devil in his role as prosecuting attorney and revealer of hypocrisy. (Given my devotion to Loki, that's hardly surprising). Deflating the pompous is both entertaining and enlightening: it's hard to follow the emperor blindly when someone is reminding you his wrinkled old ass is flapping in the breeze. And if we can laugh at ourselves as heartily as we laugh at others, we can avoid falling into the error of believing that we are marching down the One True Way.
It's important to remember that people trying to create heaven on earth have given us some of our nastiest hells. The Khmer Rouge, Sendero Luminoso and a certain failed Austrian artist were all convinced that their cause was just and their actions perfectly moral: we may accuse them of being in league with Ol' Splitfoot but they were certain that God (or history, which is just as inscrutable and all-powerful) was on their side. Their devils were their enemies - the bourgeoisie, the intellectuals, the Jews, and everyone else who didn't buy into their brand of morality. The crimes committed in the name of Satan pale beside the carnage created in the name of truth and justice.