WHY HE'S AN A-HOLE: At times, Sheldon's undeveloped social skills make him seem childlike and cute. But then you see the chilly way he treats his "girlfriend," Amy Farrah Fowler. And the way he lords his "Roommate Agreement" over the head of his best friend, Leonard. And how he constantly belittles Howard for not having a Ph.D. Really, Sheldon is just an insufferable boob who will richly deserve the beat-down you just know Bernadette will administer upon him one day. SIGNATURE A-HOLE MOMENT: Sheldon's response every time a guest comes over and sits on the couch: "You're sitting in my spot."