I like the drive up through the Delaware Water Gap National Recreation Area (Rt 209) which runs along the Delaware river on the Pennsylvania side. There are some nice campgrounds and river activities.
From there, along the way Springfield Mass has the Springfield Armory National Historic Site. There's the Berkshires in Mass and as NHIrish says the White Mountains of NH. NH's lakes region is also very nice.
Of course there's a lot more to Maine then Acadia and the coast. Depending on your likes.
Let me know if you need any Maine info.
Ed
2014 Wolf Creek 840 on 2013 Ford F-350 Regular Cab
Frequently towing a modified 2006 Jeep Wrangler Rubicon