Vietnam, Cambodia, Thailand, m1469sia.
Been there except for Cambodia. It's an extraordinary part of the world, particularly Vietnam. I've been lucky enough to have visited 32 diferent countries (including Puerto Rico, ostensibly self-governing and certainly different from the rest of the USA) other than my own. Maybe 32; I believe Curacao and Aruba are different political entities, but can't recall; they are different sociologically, in any case. This also excludes Germany and Denmark, since I didn't leave the Frankfurt and Copenhagen airports
I was supposed to go to Myanmar (Burma) and Sri Lanka but war and politics prevented me

If I could go back to one of those countries it would be India with Turkey running just behind followed by The Philippines, Indonesia, Australia and France in no particular order.
Where I've never been; if price and time were no object, Eritrea, Ethiopia, Bhutan and Brazil.
Other places that intrigue me are Paraguay, Bolivia, Argentina, Uruguay, Belize, the West African nations, Kenya, Tanzania, Malagasy Republic, South Africa, Germany, Holland, the Scandanvian countries and Russia and Ukraine and the countries of the Caucases and Central Asia (the former USSR/Russian Empire) of course.
If I never leave my country again (unlikely

), I've certainly seen a lot of the world.