My wife's a military brat; they lived in a number of foreign countries while she was growing up. I know they were in Turkey for a few years when she was little, Germany for a bit while she was in HS; a couple of others in Europe but I don't recall which.
I've never lived in another country, but we did co-own a house on Roatan (island off the coast of Honduras) for 10+ years from the mid 90s to mid 00s, which we used extensively for scuba-diving vacations. It was near the community that catered to Euro backpackers, had an abundance of fun diving & partying there.
As far as countries been to...only listing places where we stayed for multiple nights, so not including cruise day stops:
Canada
Mexico
Honduras
Belize
China
Germany
Italy
Greece
Austria
Switzerland
France
Bahamas
Hard to say what was my favorite; China was extremely interesting, in Greece and Italy the food and views were outstanding...but the early years on the Honduran islands were pretty spectacular...young, no real responsibilities tying us down (we hadn't had kids yet), seeing the amazing reef system below the sea, and the charm of being in a place where time stood still & you weren't a slave to the clock...first few trips there were only a couple of TVs in the entire town, so when you went out to dinner or for drinks you actually talked & socialized with everyone, discussing what you'd seen on that day's dives. Good times....
Been to a number of places on cruises (in the Caribbean, haven't done any to other areas). Most interesting was a week on one of the old Windjammer Barefoot cruises. They've gone out of business, but it they once owned a number of tall ships that they used to cruise the Caribbean; we spent a week in the BVI, which was spectacular. Small ship, about 40 guests & a dozen crew; nice thing was it could get to the smaller islands & to areas that the large cruise ships could not access. Day would start with breakfast onboard, then a chat with the captain, where he'd preview where we would be spending the day & let you know what the "drink of the day" was onboard, with the final, primary ingredient always being rum. We'd be anchored off the shore of one of the islands & use the lifeboat to tender to shore, with the final words from the captain always being "last tender back to the ship is at 5 pm. If you'd like a beautiful photo of The Flying Cloud, sails full-rigged, sailing away into the sunset, just get back to the pier at 5:01."