Star Trek. I want to live in a post-scarcity society with incredible technology.

How about the Simpsons? A fictitious America where a man can own a house and provide for his family with one job.

Hyrule, preferably the version from Breath of the Wild. I mean, yes there is the whole Ganon thing and one shouldn't go too close to the castle, but the rest of the kingdom is pretty chill, and apparently you can make an easy living by just lazy foraging in the countryside, or by selling a handful of acorns and bugs at random stables, or by growing a grand total of eight pumpkins.

I'll take a life as a homeless but well-fed drifter on horseback anytime over ... this. gestures vaguely at the current state of the world

The Culture and it isn't even close.

Pern!

Although the person who picked the Culture is absolutely on to something.

Nice try, truck-kun.

I like the 40k universe, but fuck actually living in it.

Stardew Valley is pretty laid-back and low-stakes. Relationships are incredibly easy--just give them a fish or a rock or whatever. I could get into it.

I love the world of TES 3: Morrowind. It's amazing mixture of green plains, harsh deserts, mountains, swamps, sea shores, islands, hills and all between sprinkled with alien like vegetation. Not sure if I wanted to live there forever (with all the slavery, undead and wild beasts), but ever since I played it for the first time I absolitely fell in love with the world and its atmosphere.

LoTR would be hella cool to live in, especially in The Shire.

I would absolutely love to just chill with my hobbit friends, tend to the fields, then either party or have a lovely dinner party at night and head back to my hobbit hole. Then wake n bake in the morning and do it all over again!

I have it pretty bad for The Elder Scrolls. I've returned to the series time and time again for decades now, primarily Morrowind and Skyrim, and spend a huge amount of time each playthrough reading every single book and immersing myself in Nirn and it's lore. I genuinely feel humbled by all of it, and something about that universe, the depth of its history with its unreliable narrators leaving much to speculation, as well as that immense sea of stars, Masser and Secunda, and the guardian constellations watching over you at night to the overwhelming swells of Jeremy Soule's music is just profoundly moving to me in a way I can't quite put into words.

My own, tbh. I guess any writer that does escapist type fantasy kinda wants to live there.

But, generally (and in keeping with your question more), not as an adult. When I was younger, absolutely. Xanth was my favorite place in the fictional world for a few years. It seemed like the perfect place to escape the ugliness of the real world.

Hobbington

Sailor moon. I watched it originally in high school and I'm still a huge fan, I would love to be in crystal Tokyo.

Roshar!

The movie from studio Ghibli Whisper of the Heart is so beautiful I wish I can live there :(

Avatar : TLA i don't even need to be a bender tbh

The world of Bluey and Friends.

Narnia! I have read all 7 books multiple times over the years and get lost in the world each time.

Stargate SG1.

Just got to take a nap one time in a sarcophegus to fix everything. Enough to fix the major stuff, not enough to be turned into an asshole.

Stardew Valley is the obvious choice, but I'll go with something more obscure and say Glie

I don't personally, but would you like to learn about reality shifting, where people really believe they can do this?

Discworld

Depends on context. Do I get fantastic powers or just regular "dump 'em in the middle of somewhere and let them figure it out"?

If the former, I gotta fix that Harry Potter world. It ticks me off.
If the latter, a version of reality where people stay true to their ideals and don't just spot random bullshit. It might be better, it might be worse, I want to see the difference.