Babylon 

As hinted by the title, the sixth episode of Mad Men is one of its richest in terms of hidden meanings and deeper truths, while still retaining its standard polished exterior and exquisite dialogue scenes, which provide further development for previously underused characters.

The main storyline concerns the agency's task of coming up with an ad campaign to increase tourists' interest in Israel, but it quickly emerges no one, including Don, who even reads the book Exodus in search for advice, knows much about the country. As a last resort, Don resorts to Rachel's help, causing the woman to come to terms with her feelings for him. To further complicate things, he later spends some time with his occasional mistress Midge, and the experience turns out to be quite cathartic. Back at the office, Peggy shows unexpected skills that pave the way for a new career move, while Roger has to deal with his affair with Joan.

One of Babylon's most important scenes is a discussion between Don and Rachel on the subject of utopia, a word whose current meaning of "ideal world" is most likely a misinterpretation of the original Greek, which means "non-place", i.e. a place that doesn't exist. In a way, that word is the perfect summation of life at Sterling Cooper, where executives come up with pitches for titillating but ultimately unfulfilling fantasies in the shape of commercial campaigns, and everyone else lives in a sort of "dream world" helping bring these fantasies to life. It is also a perfect picture for Don's life, from his mysterious past - which makes his Draper persona a utopia of his own - to his shallow womanizing, and the concept enables Hamm to shine in another great set of scenes, notably with Maggie Siff. Additionally, the episode deserves praise for the direction Peggy is taking as a character, not to mention the delightful interaction between Christina Hendricks (one of the show's unsung heroes) and John Slattery, which give Mad Men the right to be part of a very special utopia: that of outstanding television.