6. Little Sister & Big Daddy - Bioshock
Despite hardly knowing anything about these two mysterious beings during our early encounters with them in the undersea world of Rapture, the Little Sister and the Big Daddy quickly work their way deep into the psyche of whoever plays the 2007 masterpiece, Bioshock. Encountering this odd pair of creatures within the game for the first time is a surreal experience. Slowly moving towards the thundering footsteps and deep bass rumbles you can hear from very far away, you come across a very strange sight - a little girl with glowing eyes dressed like she just finished playing tea party with her dolls, and a giant, lumbering mechanical beast, armored with what looks like a deep sea diving suit made in a steampunk factory from hell. You notice how at ease this little girl seems to be around this massive beast, who never strays too far from her side. If you make the mistake of getting too close to the girl, and her guardian happens to notice this, it is something that you will quickly regret, as the lumbering armored creature quickly perks up, and dashes with the speed of a cheetah directly at you, quickly decimating you before you even have the chance to react, or even breathe. This is the Big Daddy, whose sole purpose is to protect the Little Sister which whom he has been paired. Further complicating the situation is when you realize that you need access to the Little Sisters in order to make your way through Rapture and to figure out what exactly is going on there. Getting access to her means getting through her protector, and while that task becomes more manageable as the game progresses, facing a Big Daddy (and sometimes, horrifyingly, more than one) will always bring a sinking feeling to the stomach of the player. And to top everything off, confronting these two can even manage to be emotionally devastating. As you bring down the Big Daddy, you'll hear the Little Sister shriek and cry as she watches her guardian crumble to the ground, leaving her vulnerable for you to extract whatever it is you need from her. These two characters and their powerful, almost symbiotic, relationship provide what may be the most wildly emotional and memorable encounters in a game that is absolutely filled with these types of moments. Whether you are tense with anxiety as you stalk the next Little Sister while trying to avoid her Big Daddy, whether you are breathless with fear as the Big Daddy rushes at you with the singular goal of ending your life, or whether you are conflicted about how you deal with the Little Sister after killing her guardian, it is hard to remember a duo of non-playable characters in a video game that resonate so vividly. They are among the most iconic characters to appear in a video game since the start of the PS360 era, and for good reason.