There is absolutely nothing out there that tops the experience that is STALKER.
The atmosphere, the sense of being in a real place, the dread, the uneasiness, the curiosity.
You don’t simply “play” STALKER, for me you truly enter a different world. And it is a world that doesn’t do you any good, doesn’t want you there, it is a world that goes unfazed by your presence.
Example of how open the game is. There a faction outside of a base and their planning to break in. However, as they were going with the plan a sniper from the base was able to hit their leader and broke that mission since they lost the ability to do the next part of the mission. So f up.