One of the two games that redefined the FPS genre.
User Rating: 9.4 | Thief: The Dark Project PC
Now this is one of the games that you can call "breakthrough". Creating a new sub-genre called "Stealth-action", Looking Glass Technologies not only created a believable world of technology and magic, but also created an atmosphere so tense that you couldn't even catch your breath while watching the movies between the levels. Though it had mediocre graphics, the sound, the design and playing mechanics were perfect, achieving what Jurassic Park: Trespasser tried and failed. This is the one and only game that I can't dare to play with lights out and most atmospheric game along with Sanitarium. Though I recall having bought it because a friend insisted, not because I wanted to, I immediately became addicted to it. After all these years (8, I presume) I still play it and the game can still make a 30-year old guy like me out of his seat. 
