I've only been to NYC twice, but think its a great (the best?) city for photography. Some recent shots from a trip earlier this year, just off Times Square - hoping to get back to live there for a while! Comments, or feedback on these welcome. Cheers.
For cityscapes, you can never go wrong with Dubai. See the works of Daniel Cheong on his 500px account.
Thanks for the comment Anthony - I agree, Daniel Cheong's shots are incredible. Some of his fog inversion shots are up there with some of the best cityscapes I've ever seen!