I love the north east. I never did any overnighters...but the crystal creek track is supposed to be spectacular.
Reccommendations though are as follows:
Harridge falls (30mins easy walk)
Leda Falls (few hours walk up a river...wading is easiest way so come prepared to get wet. awesome walk though)
Blue tier giant (3 hours ish....great walk in spectacular setting part of it along an old water race/flume from the tiers mining days)
Then areas like Hardings, Meadstone, Meetus and Lost falls are all awesome too.
Leslie Nicklauson is the person to talk to about multi day stuff on east coast though...her article here describes a walk i very strongly plan to do when i get chance:
http://www.bluetier.org/articles3/walk2.htm