The most hot-buttered of all soul singers, Barry White is an artist whose CDs come with a purpose. To say what that purpose is, is not for a family Web site--but it involves that thing that Mommy and Daddy do at night with the bedroom door closed. All-Time Greatest Hits collects the essential White and Love Unlimited Orchestra tracks onto a packed CD. Are 20 cuts too much? Not with Viagra. That's a kind of medicine that grownups take.