For me it was Mac! He was ok at first, I had overlooked him in nl and ww but when I had him as a starter... I soon realised that he was one of the coolest villagers and decided I could never have an animal crossing game without him in it (on my island for nh, town for nl etc)
Beau!! He was one of my first starting villagers (part of the first 5!) and at first I just took him in because I like his design. But after a while, I think I've grown attached to him and I'm not really keen on letting him go anytime soon.
Tasha! I found her on a mystery island before I knew what personalities were, I just thought she looked good but she is the sweetest, loveliest squirrel/skunk ever and she’s never leaving my island!
Cherry and Snake. They were my starters and I was thinking of moving them out at first, since I haven't really cared much for either uchi or jock.
The more I got to know them, though, the more they grew on me. Cherry is really sweet, although she can be a bit brusque, and Snake is (in my head) really a lazy posing as a jock. I couldn't imagine the island without them, so I'm glad I kept them and got to know them.
zucker! i’ve known about him since new leaf but was never super fond of him; i didn’t hate him or anything, he was just one of those villagers who never appealed to me aha. so when i found him while island hopping, i invited him solely for the fact that i knew a lot of people were looking for him and he’d be a fairly easy way to profit,, but my plan backfired when i grew attached to him and now he’s a permanent resident on my island
For me it was Hazel. I remember fencing her in because I didn't want to see her. Then she kind of grew on me, and now I got her picture and we're good friends. It was a coming-of-age friendship.
I'd never heard of Billy or Plucky before starting NH. When I met them, I was like "eh?" about them, but have since grown to value them as treasured members of the island founding squad.
Other shout-outs to Admiral and Miranda. I had never heard of either of them, and both were random move-ins before my island was full (I think Admiral was the tenth). I looked them up and again went "meh" but now I love them. Idk about "keep around for eternity" love, but they just both work so well with their personalities and have appropriate houses and right now I just can't see them leaving.
Nan. I had never heard of her before as I hadn't had her before. But I found this little black goat with candy cane like horns on an island and decided to invite her and see. Her house is gorgeous and she's just adorable. I may have gotten Chevre specifically because of Nan.
Rudy and Lily - I never paid much attention to them before (or at all). Rudy was my starter and Lily was one of my first four villagers; I found her on a mystery island. Initially I wasn’t thrilled about Rudy because he’s a jock and I was kinda iffy about his design, but now I love him and his design so much (in spite of the muscle talk that I hate). I thought Lily was cute right away but saw her only as a temporary resident. She still is only on my island temporarily, but the choice is tough since I still want to have Ankha and Marshal on my island. I did want Lolly, but finding Sherb might have messed up that plan.
Pashmina for me. I had her once in New Leaf but HATED where she moved (in front of Town Hall...) so I just tried to get her to move out the whole time. But I saw her again in NH and wanted to give her another chance... and I really like her! I'm planning on getting her amiibo so I can get her again~
Katt was that villager for me back in New Leaf. I ran a cycling town for a bit and she was one that got cycled through and voided bc no one wanted her...after voiding her I realized I missed her goofy face and she's been my baby ever since. One of the first I scanned in via amiibo once I unlocked it in New Horizon.
For New Horizon, I would say Tabby was the character. Normally my go to peppy would have been Wendy...but I saw Tabby on a ticket island run (with katt's influence for loving unique and quirky faces) I just couldn't pass her up and she's been in my town ever since.
Audie was the first NMT island villager I found and other than the fact she was a newbie I didn't know much about her. I only found out later how sought after she was! I also have 3 wolves on my island who I want to keep forever (send help)
I also got Tangy from an island after burning through something like 20 tickets I was just glad to get a cat (my fave animal) and unique design. Now I love her and they will both be staying forever..
edit: oop I forgot Genji! he was my starter and i've always hated jocks but he is super cute and was my first to reach best friend status. I let him (and his ugly basic house go) but i've got his amiibo card waiting!