Zion National Park is really nice and not as crowded as Yosemitie as long as you start early in the morning.
Bryce Canyon is really awsome as well, because of all the different colors of red.
The Grand Canyon is awsome, but is one of those places where you need to go there to be able to experience it. A picture doesn't do justice.
I agree Yosemitie is incredible, and its even cooler if you go theere and camp out at night so you can see all the stars. The only thing about Yosemitie is that now there are WAY too many tourists there to be able to enjoy yourself unless you go on a 5 mile (or larger) hike. (Which is fine with me, cause I did half-dome in a day, and clouds rest another).
Lastly, any place outdoors where you can just stare up into the sky can inspire me. Any professional picture at
www.webshots.com always gives me something to think about if I want to stimulate my mind.