Reddit's default theme is more or less as spartan as HN, it just uses more JS for interactivity. However, each sub can configure their own theme, which tends to

Reddit's default theme is more or less as spartan as HN, it just uses more JS for interactivity. However, each sub can configure their own theme, which tends to lead to geocities syndrome. (If you're registered, you can disable themes, presumably for that reason.)