New York is a rather large and varied state. A few things that haven't been mentioned so far:
Ausable Chasm might be worth checking out. The optional raft bit is said to be somewhat of a let down.
The
Corning Museum of Glass is well worth visiting.
If you like amusement parks,
Seabreeze in Rochester is a nice little family-owned affair with a few rather notable rides: the hand-carved wooden carousel (about twenty years old, built in the traditional manner to replace an antique one that burned); the Jack Rabbit roller coaster (one of the oldest operating ones in the world), and the Bobsleds ride (largely built in-house, a tubular steel coaster type ride on a wooden structure).
High Falls in Rochester is a pleasant area to stretch one's legs, and impressive enough to be a bit of a warm-up for Niagra Falls.