I know what ADK4life is looking for.
You want really scrambly routes and a day trip loop from somewhere on NE range of Pressis!
Some good suggestions already.
Here are some thoughts about particular challenges:
Great Gulf Headwall is typical of a Class 3 (or very near to one) loose scree scramble with some interesting larger rocks at the top out. Overall rise is quite high, maybe a 1K from ravine bowl. Excellent open exposure.
Madison Gulf Headwall is more solid slab and larger rock scramble about half way up the headwall. Some exposure, but not much.
Six Husbands Knee is a challenge in few places for rock scramble on ledges, but many obstacles are set with ladders. Its steep, but assisted.
King Ravine is more of a challenge when you include the
Subway and
Ice Caves but the ascent from there becomes a steep slide route with not too many overhand "problems".
Starr Lake Trail up from Madison col is challenge near the very top with a short section of slab problem below the summit.
I have on my
"Top Ten Toughest Trails in NH Whites" list, still to do the
Great Gully Trail off King Ravine.
2 weeks ago on a Kings R trip, I got a decent look at it from Airline Knife Edge, along with a climber who had done it.
It looks like a loose talus scramble at the bottom, then need to negotiate a more serious ledge, then trail moves off gully onto a small ridge line, quite steep, all the way to top out. I'll bet this is a doosie!
The other ravine to mention is Jefferson.
Dave Metsky (?) just led a trip through there with AMC, not a well traveled route but full of cool stuff according to report!
(EDIT)
Opps, I made a mistake, Castle Ravine was the Metsky route, Not Jefferson Ravine which has no trail ascent. (EDIT)
So, tie the tough spots together with a loop and you got some fun!
The Great Gulf Headwall may be longer than your milage.
The Madison Gulf/Starr Lake trip would be cool.
Both from Dolly Copp.
The other challanges need Appalachia trailhead parking.
I hope you won't be disapointed judging your well known Huntington's experiences.
That route is by far much more difficult over slab, then all of the above mentioned.
Brownie