A fixture in Mount Vernon since 1965, the original Prime Rib keeps it classy, 1960s style.  You'll think you fell into a "Mad Men" set with all the brass, black leather, and flowers. It's a favorite for celebrating families and romancing couples, and reservations are a must on weekends. I'd say they don't need to change a thing—not the perfect prime rib or the rich, cream lobster bisque. Crab cakes and fish are as expertly prepared as the beef. Live jazz begins at 7:30pm every night. Dress is business casual, and men are requested to wear jackets on Saturday night. (Don’t mistake it for the new branch out at the Maryland Live Casino—same idea, different ambience.)