Saguaro NP is a beautiful national park, albeit, not the most unique national park. Luckily, for those who are looking for a saguaro-like setting in which to hike beneath the sun, Arizona has plenty. Here is my experience:
I traversed Saguaro NP over two days, though it can easily be fit into one. I did this because there is an East side and a West side. This national park sits on either side of a little town called Tucson, AZ (:p). And though neither side is very large, it is a minimum drive of 45min from one side to the other and easily 45min within each side. In the interest of time and to fit in other sightseeing, exploring over two mornings/afternoons made the most sense.

Oddly enough, both sides are actually pretty different from each other. While one might say that the East side is more kid-friendly and educational with more placards along trails and short/easier hikes, the West side feels like it is bursting with twice as many saguaros. The Hugh Norris, Sendero Esperanza, Dobbie Wash loop is a 6.4mi loop that gains 1200ft in elevation and really shows off what the West side has to offer. It is rated as moderate and offers amazing views of the park and all of its saguaros. The Freeman Homestead Nature trail on the East side offers several informational placards and the opportunity for off-trail rock scramble for amazing photos (1.1mi loop, 100ft elevation gain).
If a 3hr drive South of Phoenix is not an option, trails in the McDowell Sonoran Preserve in North Scottsdale offer similar views and a seemingly endless amount of trail options regarding difficulty and distance. A highlight in this region is the Gateway Loop Trail (4.2mi loop, 700ft elevation gain). North Scottsdale itself is a delight and I highly recommend grabbing a bite after hiking at True Food Kitchen in the upscale center called The Shops.