You can customise your in-game avatar, so why not your better half?
Upcoming Japanese Xbox 360 title My Wife ~ A Bride For You Only ~ lets players customise their wife's appearance, personality, voice, name and more. There are also downloadable voice packs that include well-known voice actresses like Kana Hanazawa and Emiri Kato. Various illustrators worked on the character design, giving each "type" of wife a somewhat varied feeling.
The sort of customisation the game offers does not seem anywhere near the degree of customisation that your typical massively multiplayer online game offers.
The game offers "love love" mini games as well that include quizzing each other while watching a quiz show together or drinking juice together. Until death do you part!