I really like the red when contrasted with black and darkened features, think the CS looks particularly good in red with its features and decals.
Think the GTI looks better than R, though the most important thing is to keep it shiny as red does go a little flat if not given a decent clean and polish.
To be honest there is no real bad colour on any of the performance golfs, its just preferences when you read views, all look pretty amazing in good light as most colours ping