Outside the U.S., Pakistan
It has incredible levels of natural beauty and striking diversity in geology of historical events, landmarks, and architecture, very hospitable people, and rich cultures and cuisines. They all are also extremely inexpensive places to visit for an American (barring the flight cost).
Lake Saif-ul-Malook in KPK
Mohenjo-Daro in Sindh
Derawar Fort
The capital city Islamabad
A view of the Badshahi Masjid in Lahore
Hingol National Park in Balochistan
The rightly named "Fairy Meadows" in Gilgit-Baltistan
Among many, many more places
There are disadvantages, though, for example, low infrastructure quality, as well as a lack of tourist culture. Many amenities that are basic in the Western world such as internet access and electricity are frequently lost. Also, a local guide is a must-have if you want to visit any part of the country if you have no prior connection.
The security situation has gotten much better in Pakistan over the last few years, so much so that civilian fatalities of terrorists
have plunged by 95% since their peak in 2012, and the country is getting better by the day.
I also hear Iran, Turkey, and Central Asia are very great places to visit as well.