New York is reborn every fall, and what would a new season be without new places to usher in the cocktail hour? This season will bring fresh options for ordering the perfect margarita, an eye-opening Irish coffee and rarefied tableside martini service. You may find yourself down a dark alley across from City Hall, behind a pizzeria in Brooklyn or even at the reinvigorated Pennsylvania Station. For the happy-hour hunter, here are some of the more intriguing openings on the horizon.