I took my wife on a cruise in the western Med first, I was not sure she'd like it, she did, for better or worse. We went on one in the carib because it included Havana, which she wanted to see because friends told her it was great. (It wasn't, Havana is a dump, that trip really was a bust.) We then tried Alaska which was mediocre, not like the advertisements at all.
I concluded they are best for touching on spots difficult to access otherwise. I'm not interested in any more Caribbean cruises, I'd rather just fly to "X" and stay there a week. I don't particular want to see more Caribbean islands, I've seen enough already.
I am interested in Asia and Australia/NZ. The mideast is "out" for obvious reasons right now, and we've seen parts of it last year. And we're headed to Istanbul in September for eight days (not a cruise). You might consider that mideast, but most of the city is in Europe technically. And our friend will be there as a tour guide, oddly enough the name he uses sounds like "Tour Guy".