Blenheim Palace
Just in case anyone forgot why the palace was built, it tells you in words and in art. Inside are the famous tapestries illustrating some of the Duke's battles and the note he sent informing of his great victory at Blenheim. The butler also polishes the fruit; it's just one of the many things you get to see for eleven and half pounds.
I believe this is the chapel area. The rest of the house's inside decoration is at least this good.