Yosemite was the first American national park that I visited and I still think it's the most impressive. You never forget that feeling you get when you enter the valley for the first time and see El Capitan and Half Dome towering above you. Add numerous waterfalls, lush meadows and the winding Merced River, and it’s one of the most dramatic landscapes I've ever seen.
Due to the vast size of the park and the number of trails and viewpoints, you're guaranteed to see something different on every visit. I'd highly recommend hiking to Yosemite Falls and watching the sun set at Glacier Point.