One copy of the game and one 3DS XL (bought specifically for AC). It was hard enough to justify buying one console, really, so I don't think I'd have the need (or money) for another!
I've got two 3DS XL's and one physical copy of the game and a digital copy on the Animal Crossing 3DS XL.
Though I only seem to play on one town so I'm considering trading off my physical copy but it's just so useful to hold items and stuff if I decide to reset one of my towns.