Many out-of-towners have asked us at CheapAndChicNYC for suggestions on the best way to get here cheaply. Well, here are a couple of resources to check out:

Kayak.com
Created by dudes who used to work for Orbitz, Travelocity and Expedia, Kayak.com is a meta-search engine, or search "aggregator", focused on travel booking. In other words, it scans all the travel websites for you, and automatically finds the best deals available. All your comparison shopping can be done from one site! Kayak.com works for airline travel, hotels, and car rentals. It is free to use, and they don't pad their results with booking fees or markups, either. It is THE place to shop for travel deals online, whether you're going to NYC or anywhere else. I posted a link on our blog where you can do dynamic searches directly from our site -- so go ahead and try it!

Hotwire.com
If you insist on going directly to a site where you can book without using Kayak first, I'd go to Hotwire.com. They are basically a clearinghouse for unsold travel inventory - empty seats on flights, empty hotel rooms, and unrented cars - at big savings. Because you don't see the name of the travel partner until after you book, Hotwire can get you deals that are significantly below published prices. You might not get the best flexibility or selection, but you will find bargain basement rates and fares, many times up to 50% off the published rates.