Grand Teton is more than photo ops and zoos where the animals roam free. It isn't museums, either, where magnificent scenery is merely on display. This park, unlike a picture hanging lifelessly on the wall of a museum, is a work in progress; it is living, breathing wilderness areas. Plant your feet in a comfortable pair of walking or hiking shoes, find a trail head, and set off into the woods with a sack lunch and big bottle of water. There are isolated areas in Grand Teton, too -- even on the far shore of popular Jenny Lake -- where, with a little hiking, you'll be rewarded by a pristine, forested glade with nothing to distract your attention but wild moose and an awe-inspiring mountaintop.
If you're more adventurous, take a white-water trip down Snake River Canyon, or let a guide take you up to Grand Teton's summit.
You'll never plumb the absolute depths of these parks -- no one ever will. You could spend your whole life trying, though, and have a great and illuminating time doing it.