For rides with a lot of climbing, The Civil War Century is a good option. I did a short leg of this ride this year. Registration is in April, the ride will be, I believe, the first weekend on Sept.
For the century, 6900 ft climbing. Most of the climbing happens in the first 80 miles.
I like:
-It is a lot of climbing, the first large hills are stepped and give your legs a little bit of time to semi-recover, but not much, he he.
-There is a "bail-out" 65-70 mile branching point with an easy down hill ride to the starting point. At this junction, most of the climbing has been done, I think there is only around ~700ft of climbing left.
-Good staffed rest stops and a decent lunch after the ride. (luncheon meat, sandwiches, salads, fruit, etc.)
-Cheap, $30 (this year) which included all the goodies are rest stops and lunch after the ride.
-Cars were OK and I never felt threatened...
-Don't like:
-There is very little room for "warming up" before the first big climb hits you.
-One hour drive from Rockville. But it is a straight shot on I-270, then Rt-15.
-There were people waiting for SAG vehicle for quite a while. 1-2hr wait, not uncommon. (It is all volunteer work, so it depends in the number of SAG cars they are able to get)
http://www.civilwarcentury.com/