Vault 44: Robots were programmed to kidnap and kill random vault citizens without any discretion as to who the killer was. Was done to see how people would react to constant paranoia.
Vault 58: Vault was designed to constantly cycle in different "climates" and temperatures, forcing people to constantly adapt, or be killed.
Vault 70: Everyone in the vault administered either one of two of extremly deadly, non-contagious diseases, and every generation a decision would be made as to which of the two groups would get a cure.
Vault 33: In the beginning of the vault was a complex labrynth, and a complex puzzle to solve, with the end being the actual housing complex, and exit which would open after a certain time.
Vault 66: All the hallways in the vault were very long and stretched, making it take almost an hour just to get to a bathroom.
Vault 84: Entire vault was filled waisthigh in water. Was done to test long term exposure to water.
44's results: The inhabitants never figured out the culprit until the entire system came crashing due to a power failure. By that time, only a single man remained, who currently lives out his days in extreme paranoia. Status: Failure
58's results: One of the few Vault-Tec projects that didn't end in complete failure. Though most of its residents died due to starvation, dehydration, etc., those who survived were more than ready to deal with the wasteland horrors that awaited them. Status: Success
70's results: Eventually, one plucky vault dweller found a cure for one of the diseases while it was decided the other group would be cured. Unfortunately, she was found missing with her cure as well, to which the overseer "denied" any involvement. Eventually 70's numbers dwindled, and only a handful remained when the vault's door s opened. Surprisingly, no riots broke out over any of the overseer's decisions. Status: Pyrrhic Success
33's results: Despite most inhabitants being lone wolves, one group made it through all the way to the end, beating everyone else there. Rather surprisingly, despite the ancestors achieving success through collaboration, the descendants made use of the armory and kept the vault all to themselves. Eventually, a large group of "outsiders" managed to overthrow the defenders with sheer numbers, though many were killed during the battle, and even more dead due to the vault's failing life support which was destroyed by the selfish, previous owners. Later generations learned from the parents, and took the previous incident to heart when they ventured out into the wastes, becoming some of the most compassionate to wander the wastes. Results: Success
66's results: The vault was never actually finished, due to the elongated hallways, and as a result, only the bare essentials were put in place. Interestingly enough, the residents died of mental psychosis, from a lack of any real entertainment, than of dehydration and starvation as expected. When the doors opened, some of the wasteland's most "messed up in the head" raiders began to roam the wastes. Results: Failure
84's results: The vault is still undergoing the experiment, and as per procedure, won't open for another 42.7 years. And no, no fishmen have been produced, at least as of yet. Results: Occuring