Turquoise eyes in a flawless blond setting. A fragile yet ail-American voluptuousness. She got her real start in movies as a biker’s girl in Grease 2 and soon she was, possibly, the screen’s most beautiful woman. She was pretty good too—hard-edged as her cheekbones in Scarface, beguiling as a potion in The Witches of Eastwick. But this year she transformed herself into a full-fledged actress. First she turned into a gum-chomping Mafia wife in Married to the Mob. This month she materialized before us as a sweet-souled restaurateur in Tequila Sunrise. And in Dangerous Liaisons, opening this week, she even plays a dowdy wife. While making Liaisons, she reportedly had a dangerous interlude with co-star John Malkovich. He is separated from his spouse; she is divorced from hers, Peter Horton of thirtysomething. So nobody’s perfect. Michelle Pfeiffer is 31, and she is really something.