The following four state parks are all within 45 minutes of Hector, and the last three are within 15 minutes of each other: Watkins Glen, Taughannock Falls, Buttermilk Falls, Robert Treman. With an early enough start you could probably do all four in one long, tiring summer day. You would definitely want to hike The first and fourth, both are a lot of stairs. The 2nd is a pretty flat, straight hike to one of the highest waterfalls in the northeast (higher than Niagara), but can also be seen from an overlook. Buttermilk is a nice hike, again, a lot of stairs, but if I had to choose just two, it would be Watkins and Treman. You can see Buttermilk basically from the parking lot, and it is directly on the route between Taughannock and Treman.
Ithaca proper is also worth a good half day centered on The Commons, lots of places to shop and eat.