X2 Grand Teton.
You also might enjoy a side trip for a couple of nights to Cody, 50 miles from the east entrance. The town has a world-class, five-museum complex called the Buffalo Bill Center of the West that is great even for people who don't usually like museums. Your ticket is good for two days, which you need to allow in order to see it. There is also the Buffalo Bill Dam just outside the town with a visitor center. Trolley Tours of Cody are fun and inexpensive - you can book one to depart from the convenient Ponderosa Campground right in town. Lots more to do, (though some things are seasonal like the rodeo, and won't be operating.)