9. Andrew Ryan (BioShock)
BioShock is absolutely filled with memorable moments and unexpected twists, but the death of Andrew Ryan, the creator of the underwater city of Rapture, has gone down in history as a truly iconic scene. This is the moment when the player finally realises that they've been brainwashed since the start, obeying any order that involves the trigger words "Would you kindly".
It was a major twist, unveiled in masterful fashion, and the scene is made even more powerful as Andrew Ryan gives the player character various commands, ordering them to sit and stand. The player has no control over their actions as the protagonist, Jack, does everything Ryan says.
Then, as Ryan realises his time has come, he hands over a golf club and uses those three magic words to order Jack to kill him. Blending poignancy and gore, it's an eminently powerful scene, flipping the game's entire plot on its head and serving as a fitting finale for one of gaming's most fascinating antagonists.