Some more impact full games were of course half-life, changing the way fps were made.
And MGS2, the first true cinematic experience. A friend of mine didn't want to play himself, just wanted to watch me play through it while enjoying it as a movie. A whole industry was born later from watching playthroughs!
Shadow of the Colossus is one of my favorite games, but as a defining point for games as art it's a bit late to the party. The Myst series was more successful and is a much earlier example.







