8. Water Aliens (Alien Resurrection)
Like Alien 3, Alien Resurrection was riddled with issues and is an extremely uneven entry into the series, though it clearly had several scenes of superb invention, one of which involves the xenomorphs chasing Ripley and her cohorts through water. Up until that point, we hadn't really been able to experience the versatility of the aliens first hand, as they had been relegated to stalking crews through narrow hallways and so on, but this really amps up the tension and demonstrates how unstoppable they truly are. Whether it's a flooded portion of a spaceship or simply a lake that has to passed through on LV-426, the developers would be massively missing a trick if they don't take full advantage of this attribute. Imagine the fear it would instil in the player if you're walking waist-deep through a lake, when suddenly, one of your team is pulled down below, and a full-out assault begins as you're forced to flee as fast as possible. This game should be all about scaring the living s**t out of us, and what better way to do it than this?