I've only ever really played New Leaf and New Horizons for multiple weeks at a time, so...
CF: The only villager I remember liking a lot was Mallary 'cause
PURPLE DUCK. Needless to say, though she's not my absolute favorite, she's been a permanent resident on all my main towns since then.
NL: It was mainly Jacques. Got him randomly and he was so cool. Also had him as an amiibo camper in NH on Wahu, since let him go, and later randomly came around again to my second island, Parkwood, where he's at now. According to my dumb canon, I think that he missed having me as a friend on Wahu, and wanted to hang out with me again on Parkwood, since my character looks the same on both islands.
NH: Without a doubt Bob and Dotty. Bob because he's everyone's favorite dumb-but-lovable
PURPLE CAT, and Dotty is basically a female version of my childhood pet. I love them both dearly.
Meanwhile, Punchy is attempting to inch his way into the friend circle... you're not quite there yet, buddy.