HAUPPAGUE Long Island: A sushi place called SUSHI
You may be thinking of Sushi Park on Jericho Turnpike (between Larkfield and Commack Roads) in Commack which is not all that far from Hauppauge. Sushi Park is a one-price unlimited Japanese buffet (with several Chinese offerings as well). I find the place has really good food (there have always Asians dining there when I've been which I think is a good sign) and you can't beat the price. This is the sister location to the Sushi Park in Manhattan.