Ok, this is obvious but no one has said it yet. Ride over any of the bridges from brooklyn to manhattan, preferably at around dusk (7:30ish) or when it's already dark. Well, maybe not the brooklyn bridge - even though it's the pretty, there are too many **** clueless people on foot for it to be much fun.

Brooklyn Bridge - be prepared to be photographed, video'd, and at least one emergency manuever
Manhattan Bridge (on the north side) - race the trains
Williamsburg Bridge - nice ascent, great views