Octopus because. They are very exclusive being only 4 and the 4th is one form an amiibo. And Most of them are soooooo cute like Marina and Zucker. Also Octavian is really awesome and the whole idea of Inkwell being a splatoon fanboi while being an octopus is really really cute. But if I could pick two I'd pick dogs. Bones and Biskit are two of my favourite villagers. Cookie is super cute and Lucky is just downright Awesome!
My favorite animals in real life are cats and tigers, my favorite villager is a squirrel, but I think the best overall designs tend to belong to the Deer villagers. Beau, Fauna, Diana, etc.