Email Tournament Games
Games from the annual Email tournament are archived and presented with the grid of games played. Since the format of the tournament is round robin, and players tend to use the same style in all games started at the same time, it's useful to see how each player's style intereacts with all the other players.
If you know of any other archives of games in machine readable format, please let me know. It's not hard to convert "any reasonable" format into the form readable by the viewer.