The Lakeshore Trail at Grand Teton National Park in Moran, Wyoming is a 1.8 mile out-and-back hike that leads along a small section of Jackson Lake. Along the trail you'll have amazing views of the Tetons and Jackson Lake. Beware of bears - there will be signs everywhere, but it's smart to bring bear mace just in case.
For the best views of the Tetons, head out to the far end of the peninsula that the trail follows and continue hiking long the shoreline. The trail will technically feed back into the woods and loop around the far end of the peninsula, but you'll be tucked away in the trees. There are likely more lookout points from that section of the trail but we did not have time to explore it.
Note: This GPS data is and out-and-back hike, but the Lakeshore Trail is technically a double loop that connects the peninsula that juts out into Jackson Lake. We got to the trailhead as the sun was setting, so we didn't have time to hike the entire trail with both loops, but the distance isn't much more than 3.5 miles total to complete both loops. To explore the trail in more detail, use the OpenTopoMaps map tile switch in the trail map below - zoom in to see where the tile's trail leads in comparison.