absntr -
having lived in both Chicago and NYC (and cycling most everywhere), and having been to many other major/capital cities in both the US and abroad, I must say that Chicago is an AMAZING city for cycling. Mayor Daley has done good on this one. I haven't seen it yet, but I head that Millenium PArk has a showering/changing/parking facility for downtown communters (for a modest fee). That is innovative and unheard of. In Chicago there are more bike lanes, the drivers are less crazy and you get to pass a chocolate factory on your way into the city.
I love NYC. I'm grew up here, I have family here. But... I definitely miss Chicago. It's cleaner, cheaper, more bike friendly, more people friendly. I don't want to turn this into a what city is the best thread. Every city and place has its own rewards. I guess I'm just saying that, as far as bike-friendly, large metropolises go, IMHO that you already live in the best... any move i/r/t to the biking criteria, will, I think, be disappointing.

Upon thinking about it for the past couple of minutes, I'm going to ammend my post a little bit. NYC has really great things as far as biking goes. It's also very cool to not have to go too far to arrive at much different scenery/riding, be it out into the Hudson Valley or LI (see NYWeekendRide thread). Also, I got hit a bunch of times in Chicago, but not in NY yet. I almost kind of just want to delete my post. I don't know.