I was at Jay earlier this month. I really wish they had more snow because the amount of advanced terrain they have is impressive.
For Vermont, I love Stowe. Long trails and steeps with the front 4.
My standby is Okemo. Trails are spread out and plenty of high-speed lifts. I only consider Killington in the spring. There's far too many criss-crossing trails there. And the crowds are a bit much. The night-life is the best in the area though.
In Maine, you really can't go wrong with Sunday River.