NYC? I would say the ultimate would be the 24 Lux....
'Fraid so. My standard film lens in big cities (and most other places too) is a 35 Summilux. That's been the most useful to me over the last 27 years or so in New York, London, Paris, San Francisco, Delhi, Athens, Istanbul, Moscow, Calcutta, St. Petersburg, Beijing and more.
So on the M8/M8.2, even though I have the high-ISO option, it's the 24 Summilux. Second choice would be either a 25/2.8 or a 28/2 -- though I never much cared for the 28/1.9 on the M8 so maybe not a 28. In my mind there's no doubt that IF you can afford the price of a decent second-hand car for a lens, the quality from the Summilux is stunning.
I've spent most of the afternoon scanning Summilux shots on Ektar 100, and sorting Summilux shots from the M8/M8.2, for a Shutterbug review. I'm in love. I fear I'm going to have to buy the damn' thing.
Edit: Sorry, just realized I was answering the wrong question: I don't know where I got the impression it was an M8. With 35mm film, a fast 35mm lens, as I said. But it's intensely personal. My wife prefers a 50 and several of her best NY shots are with a 15/2.8 fish-eye on a Nikkormat. (We now have a Nikon-to-M adapter).
Tashi delek,
Roger