1. Ravenholm - Half-Life 2
Ravenholm is a mining town in Half Life 2 in which Gordon has to traverse to get to the coast after Black Mesa East is attacked by Combine forces. The town itself was a hidden stronghold that was housing the refugees from City 17 until the Combine discovered its location and proceeded to bombard it with artillery shells filled with Headcrabs. As you would expect- the town is decimated and the inhabitants transformed into Headcrab Zombies. There is one survivor though- Father Grigori who hunts down the zombies to put them out of their misery. He has devised numerous traps and an overhead walkway to keep himself safe. What made Ravenholm great was its crossover elements of sci-fi and horror- due to Gordon encountering the level at night, coupled with the numerous dark areas that are ripe for surprise attacks by your undead foes and other creatures within the town limits. Have we missed any great first-person shooter levels? Leave a comment below.