Here's one of the most inventive methods of killing a guy ever shown on screen. Dean Cain is cornered by two guys with machine guns, and he's out of bullets. (They don't know this.) So he waits for one of them to go through the safety door, and sets a cunning trap. Spoilers ahead...
How does Dean Cain's death trap work? It's because the movie Dark Descent takes place in an undersea mining colony, in the Mariana Trench, and the safety door is designed to slam shut the moment it detects seawater. And Dean Cain has stolen a bottle of saline eye spray, which is enough to set off the seawater detection system. Result, guy cut in half — although because of the weird superdrugs the company that runs this undersea base was giving him, the guy is still able to fire his machine gun for a minute after being bifurcated.