I would make a strong recommendation for Fantasy Life. Got my wife into it pretty easily, and the multiplayer is fun, and easy to do as a couple.
Fantasy Life is incredibly tedious in that ALL the crafting is all basically silly timed button pushing. (I always think of Sawyer on Lost in a cage pulling a lever to get a dog biscuit when I play this dumb game.) Smithing plays a lot like fishing or mining. The cutscenes are incredibly longwinded and tedious. The music--unlike that of Animal Crossing which is pleasantly varied--is a chirpy and upbeat to the point where it will drive you nuts after about two hours.
Animal Crossing I have been playing in dribs and drabs for the last 6 months....The real time gameplay is what makes AC greater than HM for me. With Harvest Moon--just about any of them from GBA onwards--the fast time makes me want to play obsessively or not at all. The thing that makes AC so pleasant is the way it gradually reveals itself AND curbs obsessive behavior with diminishing returns. If only Harvest Moon (any of them: SoS, 2 towns, ANB) had real time game play, I might not be selling it on eBay in a month or two.
Story of Seasons really feels like a rushed version of New Beginning: there are typos, sometimes the animation seems sluggish, and I've been having crashes. (All my other games work fine, so I doubt it is the hardware.) Does 3D add anything to new HM? I doubt it. I find myself going back to the old DS version of Harvest Moon. The UI is a little tedious--weren't a lot of early DS games stylus crazy?-- but overall it was a wackier, more fun game. Something about the 3DS Harvest Moons just leaves me cold.
Back in the 80s and 90s, the "girlfriend games" I remember were Starflight II, Escape Velocity, Master Of Orion, High Seas Trader, Sierra Adventures (King's- and Space- quests) and Infocom. 3DS games, whether for girl- or boy- friend, seem a whole lot less literate and much more mindlessly repetitive.