I'm going to work in two dimensions - place and time

Yemen in the early 2000s, though I don't think it would be as appealing in today's political climate.

Moscow in 1979 (though I imagine it's changed quite a bit since my most recent visit, circa 1990)

Bamako and Ouagadougou for music.

I'd echo the positives of Iguazu Falls, though it's something less than my absolute top-tier favorite. Sudan, which someone mentioned, didn't have much appeal to me, nor did Somalia, for that matter.