I can't really see this thread going anywhere productive but I'll flame on with some minor pet peeves about my fellow NYC cyclists (who are usually pretty good to each other):

1) Cyclists who leave their lights set to blink/flash while crossing bridges. There's no traffic to warn so turn those puppies on steady!
2) Getting shoaled by slower cyclists repeatedly over the course of several lights. If someone is faster than you, don't stop in front of them.
3) Cyclists circling slowly at lights. Do everyone a favor and put a foot down or trackstand.
4) Cyclists that get mad a cabs or other drivers. I've totally seen some road-rage incidents involving truly petty stuff and if you can't get over the small things then the city isn't for you. Save your anger for when something actually happens.