Perhaps my all-time favorite destination is Yellowstone National Park . Since I live in the SF Bay area, I guess you can say that getting there is half the fun, since we have to come all the way from the West Coast and include many stopovers along the way. I've been to the National Park 5 times...once before the fire, another just after the disaster and then 3 more times after that. We have only visited the park during the summer, but from what I hear, the winter is spectacular there, along with the other seasons.
Old Faithful is considered to be the main attraction, but the Park has a lot of other things to see. We hiked partially down to the River, but didn't go all the way down because the stairclimb was steep. What goes down, has to come back up. It's quite simple to drive through the Park and see quite a number of sights in 3 days. Great views of the Upper and Lower Falls, the Yellowstone River, Mammoth Hot Springs,