rumor at gore is bad ass but is way to short of a run,
i would have to say ripcord at mt snow and the trees trail to the right side of ripcord when you are skiing down ripcord are pretty difficult as well, i have not really skiied that many difficult trails on the east, i find plowing thru a shitload of pow in the trees outwest much more difficult than anything steep out here on the east, but that is just my opinion,
also i believe it might be at stowe called the goat or something, not too sure because i was probably 14 when i skiied it but one of the harder trails on the east as well