There is a beautiful map in Superman Returns on Lex's Yacht. if you pause the scene just right and zoom in you can see the relative positions of Gotham and Metropolis are New York and Jersey City. Gotham is the more sprawling one but Metropolis is the more advanced one. The fictional cities is what #2 is so everybody is reading #2 wrong
edit: Okay guess what I found: Atlas of The DC Universe apparently based on their research New York City still exists in DC-verse, Gotham is apparently located in the far south of New Jersey (which makes sense, Gotham is much more Jersey-like anyways) and Metropolis is in the far south of Delaware (Strange place but okay) unfortunately the map is a bit hard to read and there is now mention of some of the newer stuff like Bludhaven (One of my fav cities)
edit 2: and just for bonus, a map of Gotham