Simple:
The largest contrast in home console gaming was Pre-NES and Post-NES
The largest contrast in handheld console gaming was Pre-Game Boy and Post-Game Boy
The largest contrast in computer gaming was Pre-Windows and Post-Windows
The largest contrast in cellphone gaming was Pre-iPhone and Post-iPhone
Each easily the most influential in their respective platform arenas, causing the most change, causing the most contrast of before they existed and after they existed.