Where to go next after Tibet?

I have about 4 days left after my trip to Tibet.  I have been struggling to decide where to go.  My flight flies out from Shanghai, so, I have to make it back there before my flight back to Canada.

Option 1:

Chengdu - Stay in Chengdu and then fly to Shanghai before heading back.  This will be the cheapest, least tiring option.  I will get to visit the cute little pandas.

Option 2:

Shanghai - Fly to Shanghai right after the trip, and lux out on 5-start hotel.  Pamper myself before heading back on the long flight.  Not cheap at all, and will probably drive me nuts.  I really do not like Shanghai.

Option 3:

HK - Fly to HK and visit friends and family.  It will be VERY tiring and exhausting.  I will spend the 4 days eating non-stop, and gain all the weight back from the trip.  But this will be so much fun to see everyone else again.

Option 4:

JiuZhaiGou - a very beautiful national part - pristine scenary and waterfalls.  I will get to stay in a Tibetan family guest house.  I will be a bit of an adventure as I am traveling off the beaten path by myself.  But it is so exciting.

So hard to decide...