Buttermilk is an accessible gorge with a nice series of waterfalls in the lower park and a peaceful reservoir at the upper park.  At least one ranger reportedly resigned after they plunked a big orange Home Depot right across the road, but the park still has its charms.  It's worth noting that I've never seen an entrance fee collected at the upper parking area (from Ithaca, go south on 96B, turn right on King Rd).  Buttermilk is also close to the Sweedler Preserve at Lick Brook.

Links for Buttermilk Falls State Park:
http://www.priweb.org/ed/finger_lakes/buttermilk_falls.html
http://gowaterfalling.com/waterfalls/buttermilk.shtml
http://images.beggerlybend.com/photos/gorges/bf/
http://www.angelfire.com/ny4/waterfalls/buttermilk.html
http://www.cayugalake.com/ithaca/buttermilk.html
http://nysparks.state.ny.us/parks/info.asp?parkID=25