Starting at $395, the Hotel Gansevoort in the Meatpacking District offers a Stars and Stripes package that gives you access to their rooftop lounge and pool. A couple drinks are included in the rate along with a nice little morning-after breakfast so you can stuff your face with carbs and grease to combat the hangover. It's super trendy, so try to leave your jean shorts and red white and blue golf shirt in the room.
If that doesn't do it for you, 60 Thompson's Above 60 Rooftop Bar is open to hotel guests and members only and offers totally kickass views of the city, fireworks or not. They're really into cocktails with exotic fruits (think Lychee) and the place has room for around 100 people or so--all gorgeous, by the way--so consider it an intimate affair.
If you want to, you know, pretend you're in Miami or on a cruise ship or whatever, check out The Maritime's Cabana Bar. If you've got a room, you won't have to deal with the dragon who works the door whenever we show up and you won't be charged a cover (which only exists on busier nights anyway). Last time we went, they even gave us free passes to the New York Sports Club right down the street and, uh, after spending Independence Day scarfing hot dogs and binge drinking, you might need it.