1998. HALF-LIFE sends a shock through the game industry with its combination of pounding action and continuous, immersive storytelling. Valve's debut title wins more than 50 game-of-the-year awards on its way to being named "Best PC Game Ever" by PC Gamer, and launches a franchise with more than eight million retail units sold...
I remember playing this on a Radeon 9550 GPU with 128 MB VRAM and being amazed at how well it was running at 1680x1050.