I gotta put a plug in for my club's event on May 12...the Quad County Metric
http://www.suburbancyclists.org/quadcounty.asp It's a great ride & the best stocked rest stops in the mid-atlantic!

But, I have to admit, my favorite ride in the area is the Lancaster Covered Bridge Ride in August http://www.lancasterbikeclub.org/cbm.php

here are some pictures from last year that I found when I googled it
http://groth2005.princeton.edu/~grot...CBR_2006.shtml