i dont know how tourists like to visit the US. do you usually go for a cross-country tour? visit landmarks? just goto a given city?
it's not like we have ancient stuff to really visit. And most things are so far apart, you really can't wing it.
Never went as a tourist, but had a few conferences in California where I went out to visit the surroundings a bit. It's not as much beelining the attractions lined up in a guide as it is getting as much of a feel of the place as one can while just passing through. It's the sights, the food, the general life. Pretty much like I do in any non-US city I end up in for a few days.
As a European, the main issue is the scale really. Everything is
so far apart... Even in a relatively modest city like San Diego, places like the Old Town, Downtown or the beaches on Coronado island are desperately far from each other that walking is pretty much a non-option. San Diego was sort of ok with the tram, but LA was a pain to move around with the subway and stations so far apart. Pasadena/Santa Monica felt a bit more human-scaled.
As for the places of interest, well, to me there's always the Americana (old West leftovers/reconstructions like the old town in San Diego, Hollywood Boulevard, I-wish-the-Pam-of-my-teenage-years-was-there Malibu beach, your civil war stuff...) and the landscapes (La Jolla in San Diego has a lovely coastline - I like coastlines - and well, you have some spectacular sights like the Grand Canyon). The planet has the same age in the US as everywhere else, a scenic spot is a scenic spot no matter the flag on it. And then there's the local take on your hobbies/interests, as in visiting the local sports club or microbrewery. It's always neat to meet up another crowd to see their take on your thing.