NYC. Really everything, as one might expect, but each to its own niche, and often these niches will never meet. The highest quality drug relatively speaking that I've cold copped here has been hard (crack), with dope a very close second, but thriving markets exist for just about everything. I don't smoke pot but understand that it's ubiquitous, high quality (generally, and sadly for the demise of local and upstate grow ops, California drop ship with a tax) but pricey here, which goes for just about everything. For most drugs though you'll need a connect, ask a random person at a rave for "molly" or a random guy in the hood for dope/coke and you stand a good chance of getting total shit, largely because open air is nearly dead in most of the city. But as far as specialties go, whatever your poison is, you can get top shelf. We're so much as a city connected everywhere else quality everything can be had, it's just often at a higher price and you have to know where to look.