It's the sloppiest good game you'll ever play. A lot of basic elements you'd usually want from a game they completely dropped the ball on but S.T.A.L.K.E.R. really knows what it's going for in spite of this. The flat landscapes and cutscenes don't immediately seem inviting, but this game really wants you to be absorbed in its world.

An incredible atmosphere and dynamism permeates the world of S.T.A.L.K.E.R. in such a way that it constantly feeds into new content to see by sheer virtue of its everchanging quality. Missions may be randomly generated and often worthless fetch quests, yet it doesn't matter because I've been low on health from fighting off bandits and arrived at an area desolated by Bloodsuckers. Amongst all of the flaws, I think the number one quality at play here is that S.T.A.L.K.E.R. functions as an endless generator of stories. All the other people you meet in the Zone are extremely experienced and demotivated mercenaries, because the Zone is hell. Everyone has an understanding of what this place is, and you see them sit down gathering around fires to tell stories, spread rumors and play songs just to keep morale up in this place. This is a mentality that you'll see spread to fans of the games, with the fanbase often having a sense of comradery - and this is because even playing the game leaves you with tales and knowledge you probably won't forget. I'd like to ask for stories in the replies of this post for peoples first encounters with mutants, or really any interesting things they remember from this game as a testament to this. The game may not be perfect, but it'll give you endless memories of a true wasteland.