If you swing by the Pittsburgh area, I had a pretty decent route up the Eastern seaboard. Went up and down 3 different times in a 172. I'll try to remember some of the cool places. Unfortunately, my trips were mission based, so not too much exploring. Farthest North I went was Pittsburgh.
Roanoke is pretty scenic, especially when the sun is low.
If you want to get some interesting ATC experience and/or scare your self a little. Head into Manaasas in the SFRA, just south of DCA.

If you swing by Norfolk, a fun way to cross the bay is low and slow following the bridges.
I'll try an remember more. I'm actually jealous you you doing this in a 150. Not that the 172 needs that much more room, but I would have definitely felt more comfortable going into some of the more scenic and smaller airfields in something smaller.
What's your destination in Florida?