Squirrels! My fella pointed out to me that I'm a little crazy for the squirrels in this game, and have to admit I think I love all of them! hazel is probably my favorite though. I think she's insanely adorable on all levels.
Weirdly, perhaps, I am totally in love (of sorts) with Dr. Shrunk. He's so cute and funny/not funny...and the way he dances when KK sings with his little tail sticking out of the seat of his pants is sooo cute to me!
But then there is the very cute Digby and the sweet Blathers and Celeste.
ETA - or did you mean villagers only? On that I can't say as I love several to death. I had an easy time with the "animals" in the non-villager aspect.