Each of my villagers has a reason either nostalgia or superficial. My current villagers are Pango, Beardo, Caroline, Lionel, Muffy, Rosie, Felicity, Ankha, Molly, and Freckles. Molly is going to my sister and Freckles I hate with a passion cause she just moved in without my consent and is currently in the middle of my front yard. My last two dreamies are Maple and Lucky. Now for the explanation of each:
Pango: She's the only original villager I have left in my town from when I started it up almost a year ago. I'd never had her before, but she quickly became friends with my mayor and has remained one of my best friends since the beginning. Everyone else is gone and replaced, but she's always been in my town and hopefully always will be. She likes to send me letters and pop in for visits every now and then. She's also given me about 6 pictures of herself. All in all I gained an unexpected attachment to her.
Beardo: When I first saw Beardo I was like "Dude, I need dat stache in my town" And I actually got him in my tent once and could have picked him up, but that was before I knew you could just spam the tent villagers and bully them into your town so I lost a game to him that would have made him move to my town and so I got sad, and it wasn't until the next day that my sister told me I could have kept trying. In the end she stumbled upon someone on a forum that had him moving out and I had room and so she let me have him for free

I call him my mayor's husband in my town cause his house is kind of close to mine (but not obstructive *cough cough Freckles*) and every time I see him I just giggle.
Lionel: I wanted Lionel for the exact same reason as Beardo: He has a rockin mustache. He and Beardo are my Stache Bros and I have sent them Mario and Luigi shirts respectively a few times because their houses are kind of close together and I think it's really funny. Lionel is kind of my mayor's gay best friend because I once delivered a shirt to him from another villager and he tried it on and his only complaint was that it needed more glitter. XD
Caroline: She was completely an impulse pick up. I saw her up on reddit for free one day and I said "sure why not she's cute and I have an open spot in my town." So I picked her up with the intention of one day trading her out, but she found a little place in my heart. Caroline is actually a nostalgia character for me because in the gamecube animal crossing she was my very first town's island villager and I thought she was cute then and I still think she's cute now. I recently thought about letting her go in order to get someone else, but the more I thought about it the more I realized I would miss her if she left. Even if her house is awkwardly sandwiched in between Beardo and Lionel making it hard to plant bushes, I still really like her and don't ever want her to leave.
Muffy: I picked up Muffy because the previous uchi that I had picked up (Mira) moved out without even telling me! I played one day and saw her and she never pinged at me and then the next day I didn't play cause I was too busy and then I logged on the next day and her house was gone and she just sent me a letter like "Oh hey, I moved kbai" :< But Muffy was a welcome addition to my town even though she's kind of off in her own little lonely part of town atm (Maple will join you soon enough). She truly is the "black sheep" of my town.
Rosie: Rosie was one that I wanted because I love cats, but when I was originally picking out villagers for my "dream town" I debated on her because I wanted like 4 cats and I thought that was too many at first, but then I was like eh, whatever give me ALL THE CATS. And it just so happened that my sister found someone who was selling her for a relatively low price for Rosie, so we bought her for 5 million bells plus a bunch of hybrids which they were all mostly extra hybrids anyways. She's adorable and funny and I love seeing her around town and interacting with other villagers. She is one of my favorite AC villagers of all time.
Felicity: I wanted Felicity so bad the first time I saw her cause I was overwhelmed by her cuteness. Like I feel like if there was ever a villager to represent "me" it would be her. There was no doubt in my mind that I wanted Felicity in my town from the very early planning stages of my dream town and she's part of the reason I almost didn't pick up Rosie at first because she's another peppy cat, but then I decided who needs jocks or cranky villagers? I don't understand why she isn't as popular as she is because she's just absolutely adorable and I love her!
Ankha: I wanted Ankha because her design was really cool and I thought she was really unique when I first saw her. And since she wasn't another peppy cat and actually offered a bit of variety that I actually needed personality wise, I didn't say no. My only regret with Ankha is wishing I would have waited for a better deal on her. My sister paid 20 million to get her for me and after the fact I found her several times on reddit for free. But she's in my town nonetheless and I thoroughly enjoy having her. <3
I know these two aren't in my town yet, BUT I wanted to give an explanation as to why I wanted them:
Maple: I originally wasn't going to have Maple even though I thought she was so cute I could die. But I originally had Lolly (the 4th cat) planned as my other normal villager because I really liked her, but Lolly basically pulled a Mira and I logged on one day to find her in boxes even though I played every day and talked to her and passed her and she never once pinged! But I decided that instead of doing a risky 16 cycle to get Lolly back I would pick up Maple instead because I do like her and if I weren't getting her on my main town I would probably have ended up getting her for my cycling town eventually. She's currently sitting in my brother-in-laws town (which is controlled as a bit of a holding town by my sister, she also has Marshal waiting for my cycling, but he'll probably end up in my main for a while until I'm done cycling then I'll transfer him, but anyway) I think she's cute and in a way I'm glad that I will be getting a bit more animal variety in my town. :3
Lucky: I originally never even thought of Lucky. I've had him in previous games and never paid much attention to him, but he showed up in my cycling town and even though I'm giving that Lucky away to someone else I have been enjoying him while he's in that town. One of the main reasons I'm swapping him for Marshal on my main's dreamie list is because the inside of his house is decorated with Egyptian stuff just like Ankha's and I want them in a town together. Plus my cycling is in need of a smug and my main is in need of a lazy, so it works out in the end.

I never realized how much I liked lazy villagers until I got my cycling town and had like 3-4 at the same time. They're just funny and they channel my inner fat kid. ;D