As Seema suggested, I consider South Hancock one of the best sled runs (of the peaks I've tried so far.) I prefer South Hancock to North because it isn't quite as steep and has fewer trees to contend with. It is fast, even down South Hancock, so be careful though!
I swiss bobbed down Liberty Springs trail a few weeks ago. At that time, the trip from the Franconia Ridge trail junction down to the campsite was my best sled run all year. Below that there were too many rocks and too much ice to make it much fun. Hopefully, some snowfall will help with that.
Tecumseh also makes for a terrific sled ride, you can slide about 2/3 of the way down the trail. Moosilauke's Carriage Road is also pretty good provided snow conditions are okay.
I have not tried sledding Crawford Path... it might be more difficult than some of the others listed above because it's such a popular trail, you would have to be very careful to avoid other hikers.
- Ivy