Strauss Zelnick avoids vice. His company makes billions selling it. The longtime CEO and chairman of Take-Two Interactive Software is the straight-laced leader behind one of the bestselling and most violent entertainment properties of all time, "Grand Theft Auto." In the gritty crime-drama series, which is set to reemerge this fall with its first new installment in 13 years, players engage in gun fights, bank heists, drug trafficking, and sex with prostitutes. Zelnick, who's in charge of ensuring "GTA VI" lives up to its world-historic hype, is a family man, philanthropist, and workout buff. He says he doesn't drink, smoke, or own a gun, and he's never gotten so much as a speeding ticket. "I train most days, sometimes twice a day," the 68-year-old tells me in a wide-ranging interview at Take-Two's Manhattan headquarters.…