I suggest Kennywood. I've been to both, and I enjoyed KW much more than HW.
HW is a nice park, but it is very small and doesn't have as much to offer as KW. Legend is one of my top woodies, and at risk of being flamed from here to eternity, Raven is IMO, a good-but-not-great coaster (I just don't see what all the fuss is about). They have a decent collection of flat rides, and a waterpark that looks OK (I don't do waterparks). And the free Pepsi and parking, along with the great staff make it a fun place to visit.
KW however, is a blast. They mix the old (Thunderbolt, Jack Rabbit, Racer) with the new (Phantom's Revenge, Exterminator) beautifully. KW's collection of flat/vertical rides is extensive, and also mixes old (Turtle, Whip, Roll-O-Plane) with new (Aero 360, Pitt Fall, Skycoaster) very well. Add some Potato Patch fries, and you have a fun-filled day.
If you do decide to go to HW, I would second Joe Carroll's advice above and go to SFKK as well. It is only about 2 hours away, and will complement your HW "wood-only" coaster diet very well.
Wherever you go, have fun!!!
Jon