As a Williams College student, I visit Jiminy quite often, since it is only 15 minutes away. On my first visit I was quite impressed with the mountain. While it is much smaller than northern resorts, it is the largest I have seen in Massachusetts, and it provides a good variety of terrain. Its double-diamond trails are about the difficulty of a diamond at larger resorts, it has plenty of snowmaking, and the night skiing is great.
One thing to be wary of: the lodges have tiled floors, which are dangerously slippery with ski boots on.
Pros: Close-by (Western MA), Night skiing, Trail variety
Cons: Relatively small, Floors in lodges