A note about NYC pizza. My family has been in the NYC pizza business since the 50s. My grandfather came here from Italy and opened up our family pizzeria in Queens in 1957, which we still own. I used to work there as a pizzaman for years. So it's safe to say that I'm a pizza snob.
Somethings you should know about pizza here. There is a ton of it, and a lot of it is crap. You have NYC style pizza, and more traditional style pizza cooked in brick ovens. There are places that are considered the "it" spot, but I've found that most of them are nothing special. Just hipsters hyping shit up.
For NYC style pizza, check out Joe's near Bleecker St. Solid slice. Unfortunately, Sbarro's is a chain, and is not very good. I wouldn't recco it. There are also a million Ray's, and most of them aren't the original.
For traditional brick oven, you'll hear folks mention Grimaldi's, but that's overhyped imho. You'll wait on a long line, and there's nothing special about their pizza. Check out Keste on Bleecker as well. The owner is Neapolitan, and has his ingredients shipped from Italy. The pizza is to die for.
Now I'm hungry.