I was supposed to go see the Civil Rights Museum in Memphis when I went - but we ended up having time to visit only ONE place during my trip, so that was a no-brainer: we went to Graceland.
It's a cool place to see. (and you can believe I found a way to exclaim "great shades of Elvis!" while I was there)
I'm sure the Grand Canyon must be a great place to visit - haven't been there yet, but that's definitely a place I want to go to.
I'd totally suggest you visit Alaska, but that's kinda far from the rest of the country to begin with... It's so worth seeing, though. Magnificent place.
Las Vegas might be fun to see as well. I haven't yet, but it's on my list.
I believe it doesn't really matter which state you're in - you can find great things to visit anywhere in the US. It's just a question of doing a bit of research on the state or the city where you'll be. I have yet to go anywhere where there wasn't anything really fascinating to do or see.
