I simply cannot choose one, so... Ruby, Carmen, Claude and Gaston. When I heard Claude was coming back in Amiibo Card form, I actually cried. I had him in a old town and he was my favorite villager. I have had Carmen since the inception of New Leaf and of course, Ruby is my spirit animal, lol. I love the rabbits. I do believe that with the exception of my all same species towns, I have rabbits in all of my other towns. I am also going to be creating a new town of all rabbits this month. Better late than never!
Entirely too difficult a question to answer! If I put one down, I'd have to put them all! Let's just say that my 'can't live withouts' are Ruby, Carmen, Coco, Claude and Gaston. I have each of them in multiple towns. I even made my town of Harvest a Coco-centric town all her own with her own flag.