-Gayle - she's pink alligator with heart on her snout, gorgeous blue eyes and sweet normal personality - her being (cute) alligator is quite unique as often when you think "cute" your first thoughts are rather about squirrels, cubs, hamsters or deers, and here she is - pink 'gator paired with cutest personality ever.
-Nate - at first when I've moved into my town I hated him and wanted him to go as soon as possible - he was that creepy, green mono-brow bear with nothing interesting about him, but time had passed and once I spotted him talking with other villager (guess it was uchi) and he just burst into tears (over melted ice-cream, no less) and it was paired with text like "mwee mwee" (lol) that I couldn't help it - he was so cute that somehow it all made me do 180 on him - now he's my sweet, overgrown teddy-bear
-Caroline/Tutu/Chops/Naomi/Del/Puddles - I just really liked their design/color scheme - Caroline has clashing colors of red and blonde with blue eyes, Tutu is a polar bear (and one of better designed bears out there too), Chops, well, I noticed not many people likes pigs and I kinda did some research on pig villagers and he looked fabulous with that moustache and chinese shirt and same goes to Naomi (plus she have nice eyes), Del is alligator and froggy is all pink
Also, because they're low tier, so kinda rare and I'm real sucker for unique villagers. Yep, I'm shallow, just like that.
I'm also trying my luck with villagers like Marcel as they the ones that probably stand out the most. Just lately had an idea that if I ever reset my town (almost no chance) I would like to do a town with kinda japanes-y/theatre/distincitve looking villagers like Marcel, Kabuki, Pietro, Chester, Analisa, Greta, Genji, Snake, Muffy and either Clay or Flip.