What would it be and why? mine would probably be bunnies!
(I came upon this question as I was compiling a list of my dreamies and was torn on whether I should include two of the same species in my town or keep everything balanced...)
Surely Cats, wolves or dears! They're so cute and different, in beauty and personality, but If I have to pick up one, I choose cats!
Most of my fav are cats and I really love them, but for the "theme" and the name of my town also sea creatures, like Marina, I love her
I would choose deer for sure. I think it's a real shame there's only eight personality types in this game. If there was ten and I'd be able to have an all deer town. Without missing out on certain public works projects.
Deer - but rabbits would be my second choice. The deer villagers are my favorite species, but there's a good variety of rabbits in the game, and many of them are pretty cute.
I second everyone who's said deers. I like some of the other species equally, but just think the dear have the most visual variety (i.e Erik looks very different than Beau, Deirdre very different than Fuchsia).
I love almost all of the wolves, but their overall design (shape, not color-wise) is completely identical.
Used to have a deer-only town way way back when I actually played. Was by far my favourite species by then but it was a hard time keeping up so no one left and my game glitched once so yeah I don't think I could attempt again.
If I could only have one species it would be cats. I prefer having variety in looks so like have different species.
If they sort of marry together - I like it a lot - eg I have one town which has a definite African feel, a safari park! Two hippos, two lions, a rhino, an ostrich, a deer and two wolves (albeit that is stretching it a bit).
I'm making my second town into an all squirrel town! Was tempted to do wolves or deer but I have dreamies for both species in my first town already so I went with squirrels!
I feel like I'm the only one but I think an all elephant town would be really cute. I've always liked elephants in real life and acnl has so many cute ones like Tia for example.
i'd love a rabbit town! probably because i'm unhealthily attached my bb ruby :')
also, like everyone said, a deer town would be rreeeealllly nice- they have good variety in personality and their all so cute! i'd also love a dog town because i love dogs and imagine living in a tiny town irl just with a bunch of dogs??!!??! soo cute?!?!?!? god bless america
mine would probably be bunnies! 
