What inspired BioShock?

This one needs no detective work, because the creator itemised it himself. In interviews given around the game's 2007 launch, including a Washington Post interview (September 14, 2007) and a Gamasutra spoiler interview (August 30, 2007), designer Ken Levine named Ayn Rand's novels The Fountainhead and Atlas Shrugged, and her philosophy of Objectivism, as the foundation of Rapture and of its founder, Andrew Ryan.

Around that core he named Orwell's Animal Farm and Logan's Run, built Ryan partly on John D. Rockefeller, and took the city's Art Deco look from field trips: the GE Building and the Atlas statue at Rockefeller Center in New York. Even the name is a tell. As Wired noted in its own Levine interview, Ryan is a partial anagram of Ayn Rand.

And the game is openly a successor to Levine's own earlier work, System Shock 2, the cult PC classic whose haunted station corridors Rapture rebuilt under water.