On the Unusual Day she devotes to relaxing, she drives her black-cherry Corvette to the beach at Marina del Rev, California, strips down to a microbikini and shows off the shape that made her famous. "This is not the perfect body," says KC Winkler, contradicting the evidence. "It ought to be, with all the working out I do, but it's not perfect yet." Her nearly perfect shape, golden hair and aqua eyes have dazzled viewers of TV's Dallas, Growing Pains, Three's Company, Riptide and Crazy Like a Fox, but Kc first achieved name recognition as co-hostess of the game show High Rollers. She parlayed that dicey gig into more guest shots and movie credits, including Night Shift, Armed and Dangerous and the upcoming comedy Say Bye-Bye. And she just finished her first season as the paragon of the syndicated workout series Body by Jake--Kc is the tanned beauty who performs fitness guru Jake Steinfeld's exercises while Jake jokes around with the camera. "He's very funny," KC says, "but you know something? I'm one of the few people who have never seen Jake work out. I'm the one looking at the floor while he gives instructions." Her on-camera regimen, backbreaking as it seems to Jake's viewers, is a warm-up compared with the daily grind she performs to keep her condition in the condition it's in. In the mirrored workroom of her palatial Marina del Rev town house, she catches up on her reading while spending hours on her exercise bike. She does lunges, calf work, trunk twists, flutters and crunches, and works out on an evil-looking contraption called a Paramount Fitness Trainer. Pinned to the wall of her workroom is a poster--Kc in a hot-pink bikini that would show a gram of fat if one dared accumulate. "My motivation," she calls the poster. Worried that Playboy's cameras would detect any imperfection, she stepped up her workouts in May. She needn't have fretted. Now that her career is picking up speed, she plans to be selective about the parts she accepts. "You get a little tired of playing bimbo roles--ditzy blondes," she says. "I hope I can help show that there are good-looking women who can also walk and talk and think." Too late. She already has.