Well I'm going to pick some different ones.
To live in: Vault 34, aka The Boomers. The only thing that was changed in this vault is that their armory was over stocked with guns and the room wasn't locked. This meant that everyone armed themselves, trained to the point they were like a miliatary unit and then killed anything and everything that came near their vault. 200 odd years later they're still going strong so looks like a good place to be to me.
Not to live in: Vault 6. Let me just leave you with the wika description:
"The vault's original purpose in the Vault Experiment was that it allowed small doses of radiation to leak into the vault once a day, resulting in the population turning into an aggressive pack of extremely irradiated feral ghouls."
Slowly being irradiated till your skin falls off and you lose your mind turning into a mindless, disgusting animal.
