badlands & blackhills are legit awesome
i've never been to yellowstone or grand canyon, but if i was rating attractions in the US:
Redwood forest
Oregon coast
Black Hills/Badlands
Blue Ridge/Smokey Mountains
Cascade Mtn
Lake Tahoe
Gauley river/ WV
Hudson Valley
(can't really rate swamp area or piney woods area since those are 'home')
my favorite part of Badlands trip was my friend and i saw helicopter rides for fairly cheap, so were like "why not"?
get in a small helicopter and the guys just start ascending - i'm thinking :why do we just keep going up? getting harder to see stuff"
right about the time i'm getting ready to say something, the pilot just steers the helicopter into a dive and the Badlands are approaching us with great alacrity
obviously we didn't crash, but those few seconds of the Badlands are seared into my memory