As a Flyertalker, how did you end up marrying someone who has no desire visit other countries?

One technique I've used for solo travel abroad is to sign up for a 1-week language course somewhere. Learning a foreign language connects me to the culture and the history of the city, going to classes gives me structure to my day (i.e., makes me get out of bed in the morning) while still leaving me with time to sightsee in the afternoon, and provides a network of people (classmates, events organized by the school) with whom I can sightsee or go out for meals. Not to mention the fact that learning a language (even just a week's worth of classes) enhances your ability to function abroad - and makes a good impression with your existing (and future) employers.

If I were you, I'd visit either Mexico or Spain and combine your trip with a week's worth of Spanish classes. You can find a good combination of language schools + sightseeing + liveliness in places like Madrid and Barcelona (Spain) and Guanajuato and Oaxaca (Mexico).