Rodney
because he's small and sweet and adorable
but he moved in RIGHT next to me and he ALWAYS asks to buy the newly customised furniture I want for my house off of me.
But because he's so cute I can never say no to him. Or any of my villagers for that matter.
Mallary. I think she's cute (I think all the ducks are cute) and she mailed me her picture when she moved T^T but she always commented on my outfits like I was wearing them too much like... girl I got business to take care of I'm not changing my wig every day.
Marshal and Poppy, mainly how people are with them.
'OMG! Marshal senpai, please notice me!~', 'Today me and Marshal are getting married 1!1', 'Marshal Kawaii! He's so Kawaii!' and sometimes I run into disturbing art work of him on Tumblr... (Makes me want to protect him, well the one in my town at least) I see this a lot! Luckily not here tbh.
For Poppy, there was this person going around calling people villagers trash tier a while back and called all my villagers trash! Including Sally!. Poppy was their favorite villager (and they also had Marshal and those same villagers you see in over 1000 towns).
Another reason is that some treat her like she's better than the rest, which is soooo not true!