a signature hike in the Tetons is cascade canyon. you take a boat ride across Jenny lake, see hidden falls (http://gowaterfalling.com/waterfalls/hidden.shtml), climb to Inspiration point, and then head into cascade canyon (http://faculty.deanza.edu/donahuemary/CascadeCanyon,GrandTetonNationalPark )
we hiked thru the canyon to the trail junction (4.5 miles), where a mutiny happened and we hiked back out again. there was allegedly a moose in the field, but I think they were all just messing with me, as I never saw it.
it was a lot of miles for me, and I was certainly toast by the end of the day, but in a good way.