I guess one of the most sought after day hikes is for the Half Dome cables. The National Park Service now has a letter for day use permits, but they more or less come with most backpacking permits if requested. This is what it used to look like on the weekends and holidays before the permit system:
I don't know if I could do it that way. It would just absolutely beat up my body to do the 16 miles round trip. It's not just long, but the elevation gain and loss. I had enough difficulty doing 10 miles a day. The downhills may be less tiring, but they absolutely beat up on ones knees and hips. Definitely bring hiking poles and ibuprofen.