If Daddy's buying, baby, make him take you to La Sirena. But remind him to make the reservation two weeks in advance, because securing a table here at a reasonable dinner hour is impossible. Easier to persuade a Palm Beach socialite to give up her Lilly pedal-pushers or a rich man to enter the kingdom of heaven! (But Daddy loves challenges, doesn't he? That's why he's got the moolah.) Marcello's is older than God, it's the size of a matchbox, it's stuffed to the rafters with polo players and Mafiosi, with golf pros and minor celebrities, with helmet-haired ladies who regularly appear in the columns of the Shiny Sheet for the size of their settlements. Everybody is shouting at the top of his lungs; it's a madhouse! But the food is often excellent, and the wine list is a tome as formidable as a volume on divorce law. Recommended: a perfectly executed caesar salad with chopped anchovies and chunks of fried bread. Fat escargots perched on a croute sodden with butter and wine. Homemade ravioli stuffed with chunks of fresh lobster. A superbly sautéed yellowtail snapper for two. The giant scampi Marcello. And of course, since money is no object, the impossibly alcoholic and ethereal zabaglione with raspberries, and a plate of biscotti with Vin Santo. Here's to living large.