The Big Apple, the City that Never Sleeps, the city so great they named it twice - New York, New York. The financial and cultural capital of not just America, but arguably the world, New York has also been unofficially established as the center of all things meta-human. The first headquarters for Beacon was established here, and Sentry has made New York home for more than ten years. Numerous other superheroes (and villains) patrol and prowl the streets of the city as well, or use the urban sprawl as base of operations from which to serve a much larger protectorate.
While the very first Anomaly Integration Matrix was established in Los Angeles (to cope with the still-homeless San Francisco Strays that prompted the legislation), New York has since become the home of the most comprehensive Integration system in the world, with multiple AIM sites spread throughout the five boroughs. Though Anomaly Incursions may not occur here with any greater frequency than anywhere else (though various think-tanks have been attempting to monitor activity and prove otherwise) with more than a half-dozen offices across the greater New York area the metropolis is likely the best advertised and most thoroughly equipped city to process new arrivals.
Through it all, New York still has everything to offer that one might expect - Broadway shows, comprehensive television productions, fine arts centers and museums, Wall Street and the Statue of Liberty. Here too are the upscale neighborhoods of SoHo, the bohemian Greenwich Village and the sprawling Central Park, along with various seedy back alleys, poverty-stricken slums and shady warehouses. Simply put, if you're looking for it, New York has it - with the possible exception of a little peace and quiet.