I have. Three times. Once in the early 80s, once in the mid-80s, and once in the early 2000s.
London, England to visit my mom's best friend from her hometown (married an English doctor) and was introduced to both Cadbury Eggs and Weetabix, then Spain (and Portugal as a side-trip to visit friends of the family I was staying with) and finally Northern England to stay with a Scotswoman I knew who hated everything about England but for some reason chose to live there. Hell, she frowned at the suggestion that I might buy a British flag trinket as a souvenir.
I've also been to Mexico, but even though I live about five hours from the Canadian border, I've never been there.