What good is atmosphere if the beverages aren't up to par? At Flatiron Lounge (37 W. 19th St., between 5th and 6th Aves., Chelsea, 10011. 212/727-7741), resident mixologist Julie Reiner relies on the freshest ingredients available, so the cocktail menu changes frequently. Eleven different martinis, nine bourbons, and 13 single-malt Scotches are just the beginning of the extensive drink menu at MercBar (151 Mercer St., between Prince and W. Houston Sts., SoHo. 212/966-2727). The Russian retreat of Pravda (281 Lafayette St., between Prince and W. Houston Sts., SoHo. 212/226-4944) has more than 70 brands of vodka, including 10 house-infused flavored vodkas, which means your choice of martinis is nearly endless.