I have the original animal crossing for the game cube, wild world, city folk, the amiibo party and two copies of new leaf. I have pocket camp on my phone if that counts
I own all of the English Animal Crossing games and only have multiple towns in Gamecube and New Leaf. The others I have one save. Gamecube because I have two memory cards and New Leaf because I had like 5 or 6 towns, I stopped playing them after decorating towns so I gave the cartridges to my friends. I still own 2 though!
I have one NL, one WW, and one NH. At first, I considered buying another copy of NL since I didn't like my town layout in my first playthrough of the game. However, plot resetting is so tedious, and it can be time-consuming to restart your game a lot of times to get the town layout you want, so I just decided to keep one copy of the game.
1 each: gc, cf, nl, nh, hhp (but that's dlc, so idk if that counts). Hoping to reward myself in a while with ww, possibly hhd.
But basically I have all of the mainstream games except for ww...
(not counting the animal forest ones because they are exclusive in Japanese and not counting pocket camp because I don't like pocket camp, and it's only on an app/phone and not a console)
Edit: thanks for reviving this thread @/Mr_Keroppi!
I own four—one copy each of Wild World, New Leaf, Happy Home Designer, and New Horizons. I've toyed with the idea of multiple copies for extra saves before, but I'm not sure I'd stick with them even if I did (or in the case of New Horizons, it wouldn't be worth the cost of an entire extra Switch to me personally).