In many ways I prefer Kings Canyon to Yosemite. Hardly anyone there, the waterfalls aren't as high but are every bit as majestic and numerous, and the deepest canyon in North America (to the west of Kings Canyon) and the glacier sculpting to the east are more spectacular than Yosemite. The hikes aren't hard. The Cedar Grove area opens usually the third weekend of April (might be fourth weekend this year, April 25). Leaving the canyon usually I swing through south on the Generals Highway and visit Sequoia's giant forest and head back down the scary switchbacks into Visalia.
LA times article:
http://www.latimes.com/features/magazine/la-tm-cedargrove6apr06,1,6553989.story