Whiteface Mountain is great. They have a total of 74 trails, with one gondola, one high-speed quad (Face Lift, the best way to get up the mountain, brings you 1/2 up the mountain in about 5 minutes). There's one regular quad, 5 doubles, and one conveyor lift. While a majority of the mountain is "most difficult," there is a great deal of green circles (easy) and blue squares (most difficult) on the mountain. There is also an area called "the slides," which are double black diamond (EXPERTS ONLY) trails of ungroomed backcountry trails.
Also, there are a few glades (trails that go through a forest; dangerous depending on the difficultly) Most disappointing, however, were the blue square glades, which were really just regular trails. Overall, I would say the best trail is Paron's Run and Riva Ridge, which go from the summit down close to the side of the mountain. They provide the best views you can imagine in Lake Placid.