Descent was released on Steam literally days ago, which reminded me: Descent looks terrible nowadays. Out of all the games on this list, it's probably showing its age the most.
That's incredibly unfortunate, because Descent is still one of the most thrilling games ever released. You pilot your vessel down into the depths of an infested mine, fighting off robots and throwing up because your brain can't decide which way is up anymore in Descent's 3D, no-gravity environment. There's nothing else like it, and there probably never will be.
Unless we get the Descent HD remake we all deserve, that is.