Alien: Isolation is a game which will have you peeing yourself with fear. It is all about hiding, sneaking, and very little about attacking. When this alien is on the hunt for you it would be wise to stay in cover before you suffer a horrible death.
Out of all of the games on this list, this is the one that give me chills while hiding. You have to be quiet and smart if you want to play this game right. The scariest part of this game is the suspense. You never know if you're going to make one quick mistake and then suffer the consequences when the Alien finds you.
If you are thinking of adding Alien: Isolation to your collection then I would advise you to have an ambulance for when you have a heart attack.
Alien: Isolation made it into the top horror games ever made and got great reviews around the board too. If so many people love this game then it obviously deserves to be on this list.