Moving back to the West Coast was the best decision I've ever made! Cycling in NYC is like riding in a hamster wheel. One hour of loops in Prospect Park? I can never go back to doing that again.
But on the real. My favorite morning rides would be in Prospect Park but you have to alternate your loops. For example do a loop and then on the next one take a Horse Trail and the third another Horse Trail. Prospect Park does have a bit of variation that makes things interesting if your willing to do a little bit of dirt. It's the only thing that kept me sane.