The two Montauk rides are pretty good - the full ride, Penn Station to Montauk, is about 145 miles. It's flat but pretty. (Why two rides when, for all intents and purposes, they're the same ride? Every group has its politics and things got a little out of hand ) One takes place in May and one in late August.
The same guy who runs the August ride also has a ride on the North Fork. I've not done it but it's supposed to be pretty good.
I really like the New York Century in September. 100 miles and never leave NYC. You'll see parts of New York that you can't believe are the city.
It's not a century but the Bloomin Metric that starts in Norwalk, Ct is also a ride that I've always enjoyed.
The Golden Apple (westchester county) is a favorite, the Bethel, CT century (hat city cyclists) is a nice ride, but not as well supported (but much lower entry fee). If you want a tough century (but not in NY), there's one out of Torrington, CT (litchfield hills) that's outstanding in august.
I think you want to either get farther out from the City or go father in. I you go to the CT or PA places that are "in between" (e.g. Bucks, Westchester counties), it's not all that different from lots of New Jersey.
* Harlem Valley (upstate NY) for pretty farmland terrain farther out.
* "Velodrome Veloce" (if they're still running it) in eastern PA - (has prettier farmland terrain W + NW of Trexlertown than "Gap Gallop" N + NE of Bethlehem, because the Bethlehem area has gotten more suburbanized by NJ commuters looking to live in houses on cheaper land)
* farther in: NYC Century
I haven't ridden those as official events in a long time, so I don't know how good the organization and support is, so those suggestions are based only on routes and terrain.
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