When are you going? We went this last summer and had a great time, for it being out of season, although I do imagine things get really expensive and crowded around skiing season.
Like others have mentioned, the Olympic Training Facility is really cool. You can sign your life away to go on a bobsled down the track piloted by a bobsled pilot, and they absolutely fly.
High west distillery is pretty cool spot for drinks and food.
For sightseeing one day we bought lift tickets to go all the way up Deer Valley, which I would recommend, as the sights were incredible and the mountain is so big, it took a considerable amount of time to chair lift to the top and we could watch the mountain bikers make their descent back down.