Obviously good swings produce good shots but we've all seen the swing, whether it's on the range or on the course, that has made us say, "THAT is a good swing". In a golf swing there is structure, geometry and dynamics. I think what is aesthetically pleasing are the dynamics, all the pieces are moving in relation to one another. I was at a golf school this past weekend and Grant Waite was there. He regularly tells the story of when he went to go see Mac O'Grady and asked Mac what he was suppose to look for in a good golf swing. Mac answered, "A good swing has the maximum time to make minimal compensatory actions, an unorthodox swing has minimum time to make maximum amount of compensatory actions".
Here is Grant's swing, to me the best example of minimal compensations. Even though he's focusing more on teaching now, he stil makes a lot of tour players jealous :)