Bioshock

You are the only survivor in a North Atlantic plane crash, floating in the icy water as the fuselage sinks beneath you. Your only hope is a lighthouse in the distance, inside of which sits a submersible capsule. You climb in and you begin your decent into Rapture, a city hidden beneath the sea. BioShock is the "genetically enhanced" first person shooter that lets you do things never before possible in the genre: turn everything into a weapon, biologically mod your body with plasmids, hack devices and systems, upgrade your weapons and craft new ammo variants, and experiment with different battle techniques. No encounter ever plays out the same, and no two gamers will play the game the same way.