On Sunday, two series return to the airwaves — the HBO's Girls and Showtime's Shameless. Girls features as its main character a 24-year old woman who is so self-absorbed and self-sabotaging that we can't believe we're tuning in. Shameless is the American version of its British namesake, featuring the Gallagher clan of Chicago, who deal with lying, stealing, alcoholism and prurient sex. Hank Stuever, TV critic for the Washington Post, muses on why this despicable behavior has become so popular.