I have Eugene and Cleo on my island and both houses are decorated like offices. It's so boring and I feel like it doesn't go with they're personalities at all.
There are probably villager houses I dislike more then these two but out of the ones I've had then it would be Beau and Raymonds. I like the outdoors but wouldn't want to live somewhere themed like a camping area (Beau) or live somewhere that was themed around the workplace (Raymond), their homes such don't seem cosy or homely.
Butch without a doubt. For my island at least. Poor dog was just abandoned on the roadside. This is what his home looks like in NL. I like my villagers having actual homes that I can see them living in and not gags.