I'm a combination of all four.
I always come up with themes to base my Animal Crossing towns (or island in New Horizons' case) around, and that includes coming up with backstories, personalities, etc. for the player characters. I'm a writer, so I like adding those extra layers to make playing the game more engaging.
I enjoy decorating the houses, and now I kind of enjoy decorating the outdoors. I don't really play with people I don't know unless they're folks on here for the purpose of purchasing items, and I have no interest in uploading my towns or islands with the Dream Suite function, so I only really do this aspect for my own enjoyment. If my friends, or traders who are there for 5 minutes dropping off stuff, like what they see as well, cool.
I'm definitely a collector, particularly with clothing items. The bulk of my player characters' storage consists of clothing for them to wear, though there is a mix of other stuff as well, and I want the ability to have access to whatever clothes I might want at the touch of a button with the ordering service on the Nook Phone. I try to keep the storage mostly seasonally appropriate, so for example I'll sell Tube Tops to make room for Long Down Coats for Winter, but then I'll sell those coats and order clothes more suited for warmer weather for Spring and Summer. As such, it's important to have whatever I might want in the catalog to quickly access and order. I'll tend to buy every color variation of every type of clothing when it shows up in the Able Sisters' shop, even if it's not something I'll necessarily have any of the characters wear most of the time, just so I'll have it just in case. I also like having all the different types of furniture at my fingertips as well, and in all the color variations they come in, though unless I'm actively using it in a room design or for decorating the island I'll just acquire it for the cataloging purposes and sell it rather than keep it in storage, depending on what it is.
I'm not really a social person in general, but I do enjoy playing with friends who own the game and I do make a lot of purchases here on the forums, so that fits too.