I've got a few in mind. I'll fill out your form:
Villager: Lily
Why: I fell in love with her back in 2002 when I first started playing Animal Crossing because her catchphrase was "toady" which was clever since she is a frog.
Game you met: Animal Crossing
How: One of the original 6
Etc: Well, when she moved out, it soured me on the series. Back then they gave no prior notice before moving. However, shortly after a new game called Wild World came out, and it pulled me back into the series after I decided to give it another chance in 2005. Kind of a win-win too since I also have yet to miss any events in Wild World, unlike both Animal Crossing and City Folk where I missed events, because I'm a 100% legit player, and can't always be home to make every event.
Villager: Dotty
Why: Wild World's dialog was by far the best in the series. Despite lacking real world holidays, the script writing was second to none. Dotty's arrogance in wearing my designs made me both love and hate her! So, when she showed up as a camper in my New Leaf town, I had to get this annoying/lovely rabbit back.
Game you met: Wild World/New Leaf
How: random move in for Wild World, camper in New Leaf
Etc: Wild World had the introduction of the animals opening up far more than they had before. Normals talked about Moppina, and dressing her up, while they also talked about their HRA scores going up/down depending on what furniture you sent them and they put in their house. Due to these fantastic inclusions into the series, and for the ease of play any time and any place, outside New Leaf, Wild World remains my favorite in the series, so as many villagers as I can continue having in future iterations, connecting me back to Wild World, the happier I am. Oh, I also loved the fact it finally added villagers in boxes, and you could talk them out of moving- way better than "I'm gone, but here's a letter telling you I've moved, bye."
Villager: Sydney
Why: Despite Lily taking over as my favorite to see everyday in Animal Crossing, both Sydney and Yuka who lived in the same plot area in my town, I enjoyed talking to Sydney. She's a normal like Lily, and it was a nice enjoyment after Yuka who'd annoy the snot out of me! Their houses were so close too, I'd ALWAYS see them talking, too bad I couldn't eavesdrop back then. Another feature I've loved since Wild World.
Game you met: Animal Crossing
How: random move in
Etc: The original memory card for the original game I had in 2002 has long since been lost, but Sydney has appeared in my e+ town, which is nice, especially since in Japanese her name is still Sydney.
Villager: Kicks (despite not being an actual villager)
Why: It's a bit top-heavy for Animal Crossing, Wild World, and New Leaf. Yes, I wasn't a fan of City Folk, not because of the approximate 70% recycling of Wild World, but mainly the way they merged the 20% of the original *cough* mid-village cliffs *cough* with the 70%, and only added about 10% new. I'm not a fan, but I didn't hate it either. Yes, it was annoying listening to Kapp'n repeatedly, however, when you got to the city, and the first time I saw that skunk sitting on the stairs offering to shine my shoes, quite fun watching him! He was introduced as well as Phineas, and Labelle in the city (not to mention Gracie finally having a permanent spot), but for whatever reason, he just seemed to excite me more than Labelle or Phineas did.
Game you met: City Folk
How: First trip to the city
Etc: I wanted to show that despite City Folk being my least favorite, there are some nice inclusions into the series that continued with New Leaf. The City was brought back in the plaza. Gracie retained to having a store, as well as Kicks and Phineas coming back. Kicks more so since he now has his own store.
Villager: Papi
Why: He was one of my original villagers in New Leaf. In fact, the very first picture I ever took while playing New Leaf was of Papi on the bridge as I was wanting to note where the bridge was because I wanted to move it later. I took it on day 1, hated that it was right next to a house, which ironically Isabelle says now won't work because it's too close to a house- HUH? It was like that when I moved in stupid dog!!! So, over the last near 3 years, Papi has become my favorite lazy just from having him and talking to him everyday the last few years.
Game you met: New Leaf
How: one of the original 5
Etc: New Leaf does an outstanding job merging Animal Crossing, Wild World, and City Folk together. I wish they'd have put in some features from e+, but that's another story. Papi was introduced in the series in New Leaf, so now that I'm totally loving him as a villager, I want him in my future towns.