I've trained with American Flyer's in California, and although I'm not a fan of their training method (It seemed a bit too impersonal to me... They're happy to take your money, rush you thru and off to your checkride. I was just shell-shocked that my checkride was scheduled so soon after I started flying with them - about 3 weeks from start to finish.)
However, they do a thorough and good job of getting you thru the wickets of getting your pilot certificate.
Looking at the AOPA website, it does look like there are a few other flight schools in HPN
. (Don't know anything about them though)
Wings Air (rotary wing training only)
Panorama Flight Service, Inc.
Westair & Westchester Aeronautical Corp.
The only problem I can see with American Flyers is that after you're done with training and you have your private pilot certificate, they're really not set up to rent you aircraft to get that $100 hamburger. So you'll need to find an FBO or flying club that you can rent from to exercise that pilot certificate you earned or, if you have the resources, buy your own aircraft.
Bonus animus sit, ab experientia. Quod salvatum fuerit de malis usu venit judicium.