My favorite villager is Melba
She was in both my AC:WW towns and I grew very attached to her, and liked everything about her: her cute appearance, sweet personality, candy-themed wallpaper and carpet, cozy mix of cabin and green furniture, K.K. Ragtime playing on her jukebox, catchphrase "toasty," the unique way she sang a town tune, and so on. I don't have this same attachment and love of many other AC villagers. With others, I often just like their appearance (or their tastes in decorating), but don't have an emotional connection with them.
In New Leaf I'm planning on basing most of my dream neighbors on what the exterior of their houses looks like. I really want the houses in my town to match fairly well; it bugs me having mis-matched/unappealing houses. But houses aside, the neighbors I've picked are also ones I'd love to have in my town.
The ones I still need are: Pango, Gloria, Rod, Bunnie, Erik, Julian, Bruce, Paula