Till the Borg show up…
Yet another one for the Culture .
I was thinking exactly the same thing.
Culture - any place where I can help build AI warships with names like “Frank Exchange of Views” or 'You May Not Be The Coolest Person Here" can have me in a heartbeat.
John Carpenter’s THE THING
Alien/s
Predator
Terminator
Yeah, I like a challenge…
Try Harry Harrison’s “Deathworld Trilogy” world. As your gear gets better, the world adapts and gets deadlier. THAT would be a challenge!
So… you like extreme heat, lack of water, spice addiction, dangerous giant worms, religious fanaticism and brutal dictatorship? Interesting.
Another vote here for ST:TNG-era Earth: democracy, liberty, peace, prosperity, rule of law, weather control, chances to explore the galaxy, etc. The Borg are a very occasional but acceptably-risky hazard, under the circumstances.
Asimov’s Trantor, although tempting, would be just too damn urbanized for me. The only greenspace on the entire freakin’ planet is the Emperor’s gardens, and the public isn’t welcome there.
The Commonwealth of Alan Dean Foster’s books, the Confederacion of Joe Haldeman’s and the Confederation of Peter Hamilton’s are pretty similar to the Federation, by the way.
Haven’t read any of the Culture books, but I like what I’ve heard.
Those nice fellows in the Enterpise will take care of that for me. I’ll be in the holodeck 
The Caves Of Steel.
OK, so you like terrible overcrowding, rampant agoraphobia, a governmentally-limited diet, prejudice against offworlders and robots, and a relatively rigid class system? Hmm.
Another possibility for me is Dragaera. I would like to be either an Athyra (specializing the arcana of sorcery–similar to be a mathematician) or a Hawk (history buff). I would not want to be a Teckla or any of the fighting houses and I certainly don’t want to be an Easterner (short-lived and you have to speak Hungarian).
And yeast, don’t forget the yeast.
Yum!
Todos Santos , from Niven and Pournelle 's **Oath of Fealty ** doesn’t seem too bad.
What? No one looking to be the bartender at the Vulgar Unicorn?
'Way too dangerous.
Actually, the Terran Federation from Starship Troopers (the book) is a pretty good option IMHO. Its culture is a recognizable globalized and racially/sexually egalitarian version of the 1950s US, possesses regular and reliable interstellar travel, and its strategy is rather more realistic than the Federation from Star Trek.
Well, since Prince Kittycat and his band of merry men took over the town has gotten to the point where a semi-honest man could make a semi-honest living. Not nearly as much flavor, though.
The fascist overtones - more explicit in the movie than in the book, I’ll grant you - would be a dealbreaker for me.
I’d like to live in The Fourth Great and Bountiful Human Empire. Planet Earth is at its height, covered with megacities, five moons, population 96 billion, the centre of a galactic domain that stretches across a million planets and species.