Easy -- Jack's Drive-In in Wynantskill, New York. They have been around about 50 years, have only one location, and serve only hot dogs, hamburgers (i.e. "sliders"), and, fairly recently, branched out into French fries.

Brought some to my future wife on our wedding day. (We got married in Wynantskill.) Then, I became a distance runner and started to eat healthier. I haven't had a Jack's in probably 10 years.

http://albany.citysearch.com/profile...drive_inn.html