This game is not only one of the best racing games, but one of the best video games ever made. It has an insane amount of content, especially for the time. Also it would be amazing to not only have this on PC but especially GOG to make sure this game never dies. This game really pushes the PS2 hard, which kills the console faster, especially at high settings. Also there are some issues playing the game on Emulators that sometimes can't fully provide the original experience. I have played this game off and on for years, it is one of my highest play lengths I have had in a game. I have probably clocked over 300 hours into Gran Turismo 4 and I would love to have this game on GOG with controller support. The content in this game and the incredibly rewarding gameplay is something that we really don't see anymore in video games, ESPECIALLY racing games! Today's racing games don't have the same amount of effort put into them as classic games like GT4 had. I think this game could easily sell for $20 as is with upscaling options, and easily $30-$40 for some kind of remaster. If this game ever got a good quality remaster it would be game changing!!
The newer GT games are good I think but the events don't feel authentic like in GT4. GT4 also has a much longer and more challenging campaign.
The racing and events are a very unique experience that you really can't find in today's games.