You've gotta be shitting me. The USA is your best holiday??? What do you do out there?
I guess it depends on what you're into and how easily amused you are.
I said AMONG the best not the ONLY best
A few things I really enjoyed in the US among others:
Hiking in Yosemmittee National Park,
Road biking in upstate New York (Catskills and then all the way to Niagara Falls)
Helicopter ride over Grand Canyon
Skiing near Lake Tahoe (California)
Golfing in Palm Springs or Florida
Going out in the big cities
I'm not saying the US is the only great destination, I'm just saying that it offers lots a great holiday opportunities with relatively little logistic effort for relatively little money (hiking in California is way cheaper than hiking in Kenya for example)
But then I might be easy to please (or I'm good at planning my holidays) as I also had great hols in Brazil, Cuba, New Zealand, lots of places in Europe, the Caribbean, India and most parts of Africa.