If you want a challenge, hike the Hell Brook Trail. Steep -- a direct shot to the summit (eastern approach). On the west side, the Sunset Ridge has some great views but is probably the most crowded. For a little more solitude, try the Frost/Maple trails (they lead to the forehead, not the chin (the summit))
That's a late start. Note that the Hell Brook trail in the dark would make for a very slow descent. I suggest you go up Hell Brook, wander the ridge until sunset (check out the Subway trail!), and come down the AT or the ski slopes - you'll reach the road only a little distance from the Hell Brook trailhead.