In most Southwestern states, standard rules of decorum mandate that certain topics should not enter polite discussion. No talking about religion. No arguing about politics. And, for the love of all that is good and holy, no boasting about your margarita recipe. Here in the Midwest, we're free from that final stricture — so we can shout from the hilltops that Atomic Cowboy has the finest dang margarita in town. The only bad thing about ordering a margarita at the Cowboy is having to decide among all of the tempting options. Lately we've found ourselves returning to the Cadillac, a perfect blend of oaky, spicy Sauza Hornitos tequila, fresh lime juice and Grand Marnier. This masterful marg is served on the rocks (blenders are for milkshakes). The Cadillac is the perfect warm-weather drink, although you can certainly enjoy it into the winter months, thanks to the e'er-crackling bonfire on the Cowboy's kick-ass patio. (Confidential to tequilaphiles: The mix-masters at the Atomic Cowboy have begun infusing their own tequila, with honey and rosemary. Oh, life is good.)