Forest county has a bunch of stuff up in the northwest corner. Most of the trails are for four wheelers, and I haven't had the jeep up there yet to find legal jeep trails, but the camping is great, and the 4 wheelering is even better.
You can not beat some of the state parks if your looking for primarily camping. Worlds End and Ricketts Glen, both in Sullivan County,are GREAT. Not much wheeling to do, but theres TONS of dirt roads that wind their way through the Loyalsock State Forest that have great scenic overlooks, vistas, and hiking trails filled with streams and some waterfalls.
There's a ton of camping and wheeling available over in Wharton State Forest in NJ. Trails are legal because they're named ROADS that just happen to sometimes have 2-4 feet of water on em.