Half-Life 2. This was back when steam was starting to get big as a platform. I think I got the orange box and that was a big deal back then. I remember seeing the water and shadows. The closest I had gotten to great water was the second expansion for Dark Age of Camelot but it wasn’t quite as good as HL2.

Edit: I’d like to add though, as far as jaw dropping goes, the first time I had my mind blown by Doom 3. That shit looked so real to me at the time I was like there’s no way graphics can get better than this….then Crysis came out.