I never quite understood the good or bad genes thing :) Whenever my sims have kids there will be a mix of good and bad, a few might be only good or only bad, and then again, beauty is not an objective thing, is it? Some times it suiyts my family better if their kids don't get the best looks, while in other families if not looking good they will be pimped by hair and clothes until they look very good :)
That said, in my game I think Don Lothario's son looks hot, but then if Don had a 2nd son it might have turned out differently. So I can't really recommend any premades for having kids with good DNA :)