If you hike in Yosemite, the Clouds Rest hike from Tenaya Lake will put you at a nice high (10k) and central point to get a big overview of the park. (You'll be looking down on Half Dome!). But it's maybe a 15-mile hike (guessing), so that plus a visit to the Valley would be a looong day.
A shorter alternative would be to park at the May Lake trailhead on the Tioga Road and do the Mt Hoffmann hike. At 10,850 feet it's almost 1000 feet higher than Clouds Rest and it's located in the exact geographical center of Yosemite with no other high peaks nearby so you can see the whole park. Round trip to the summit and back is only seven miles. Supposedly this was one of John Muir's favorite views.
