I still don't have Starlight Shores or any of the store-bought worlds.
Out of the ones I do have, I voted for Appaloosa Plains and Moonlight Falls. Both have a clear "theme", lots of charm, and overall just look good. Also, as a real-life Animal Lover, I'm drawn to Appaloosa Plains simply because it's the only town that properly supports pets. These two are the only neighbourhoods I've really played in -- I bought the game in a base game + Pets bundle, so I'm a relatively new player without any nostalgic attachments to older worlds.
My nostalgic "first and best-known home world" is Appaloosa Plains.
Sunset Valley in particular is one popular choice that does nothing for me whatsoever. There's not enough room, many of the textures on houses and objects look garish and simplistic to me, and overall it just feels dated and unpolished. The only advantage is the absence of combined rabbit holes, meaning that opportunities actually work properly here. They really need to fix that maddening bug.
Riverview and Twinbrook have a little more character, but they just leave me cold overall. Twinbrook also badly suffers from barely having any space to add stuff.
Bridgeport is hideous. Gray and cramped and dead. I need open space and greenery or I get stressed, even in a game.
1. Appearance: Which world looks the best?
2. Lots: How good are the lots in the worlds?
3. Sims: What types of sims do you like in your worlds?
4. Flexibility: How flexible is the world? Does it work with all your expansions well? Does it look good in all seasons? What about the Supernaturals? Does it have space to place lots released with the expansion packs?
5. Enjoyment: Is it fun playing in the world?
1. Appaloosa Plains comes in first for me due to its fall colors and countryside charm, then Moonlight Falls for its "mysterious sleepy town scattered among the misty forest" feel, though it lacks variety when it comes to local flora.
2. Both of my favourite worlds are a mixed bad in this regard: some lots I love, others I loathe. Appaloosa Plains has, for the most part, good community lots that are both functional and in keeping with the small Western town theme (including the custom Ambitions lots) -- but many of its houses need a lot work. There's a serious lack of affordable family homes in the mid-price range, and most of the starters are cruddy too. Moonlight Falls also has some good community lots as well as a better housing variety -- but some other community lots, the more "modern" ones, look really cheap and out of place. They have no charm at all, nor many distinguishing features. Even though it's likely intentional, it irritates me to no end.
3. As a terrible slave-driver who usually keeps her Sims way too busy for much social interaction, I don't have many favourites except for the Fox family from Appaloosa Plains. Generally, I like outdoor- and animal-loving folks and dislike Sims who are such blatant pop culture references that even I can recognize them as such. (I can't stand most "popular entertainment", for various reasons.) I also loathe vampires as a rule. So needless to say, I overall like the folks from Appaloosa Plains more than the ones from Moonlight Falls.
4. This is Appaloosa Plains' biggest weakness due to the lack of empty lots. There's a lot of empty space, but you can barely place new lots anywhere. Seasons even nukes one of the existing (empty) houses and turns the lot into the local festival grounds. As mentioned above, though, it does at least come with a custom-made bar (bad as it is) and custom-made Ambitions lots. Moonlight Falls on the other hand offers many empty lots of various sizes -- but no custom-made lots for the other expansions. The generic versions of the salon etc. look really out of place in this world. Both towns look great in all seasons and weathers.
5. Yes for both -- though I make a lot of modifications to both towns in order to get rid of most my annoyances and make life better for the townies. As long as I like the basic theme and feel of a town, I don't mind fiddling around with it to make it "better".