I endorse the prior suggestions of both the Finger Lakes and the Thousand Islands. Unless you want to drive the whole way, fly into SYR and rent a car from there to get to the Thousand Islands. SYR, ROC, or ITH are all good for the Finger Lakes, although flights to ITH tend to be pricey because only US Air Express flies there from NYC. (Weekly houseboat rentals are also offered by a couple of companies in the Syracuse/Rochester area for about $2500/week. You can cruise the Erie Canal system, and transit the locks to cruise into Cayuga and Seneca Lakes.)

If you like music, theater, opera, etc., consider a visit to Chautauqua. It's about a 90-minute drive from BUF. (Jamestown, NY airport is much closer, but again, fares are likely to be much higher.) Click on www.ciweb.org for more information.