Cosmopolitan
Season 2, Episode 7, “The Chicken Dance” (1999) · Samantha Jones
At the wedding of Miranda's decorator, a rattled Samantha asks the bartender for another Cosmopolitan, one of the show's earliest on-screen orders of the drink that became the series' signature.
“Another Cosmopolitan, please.”
Sources: Refinery29 - The Birth, Death & Inevitable Comeback Of The Cosmo, SATC's Greatest Icon; Wikipedia - Cosmopolitan (cocktail); Tasting Table - 15 Most Iconic Cocktails From Film And Television