Oh god, so many.
For Muir Wood: Fauna, Erik, Bea, Bones, Chevre, Nan, Cole, Dobie, Henry, Lily, Marshal, Olive, Molly, Papi, Zell -- basically, there are a lot of natural-ish looking villagers that I'd love to have, or have back, in the case of Fauna, Erik, Molly, Chevre, Nan, and Zell. If I had to narrow it down to one, I think I'd like to take Cole.
For Inverness, just a bunch of other cats I'm fond of but can't fit: Bob, Kabuki, Kid Cat, Lolly, Olivia, Purrl, and Rosie top the list, but I probably couldn't turn down the other cats, either. Top one is probably Bob, who may at some point replace somebody on my current island lineup anyway.