For food quality, I'd pick 50sPT.
My nephew went with us to 50sPT a few years ago and he enjoyed it. At first, he didn't really know why the waitress was picking on him and telling him he had to eat his green beans. He loved it when she brought them back as a green bean sundae. I think it is a neat, fun atmosphere.
Compared to the buffet at H&V where the wait staff are few and the food sits under heat lamps but gets cold.