I've traveled all over the world, and I'm a coffee lover. The US has the best coffee. Some places have better specialties, like Turkish coffee or espresso, but overall, the US is flooded with good coffee.
I'm sure you find good coffee lots of places in the US, but I think the majority of what you get there is terrible. Then again, living in Oslo, Norway will get you spoilt when it comes to coffee.
There's a great coffee shop in Big Sur, though.