4. Jet Grind Radio (Sega/Dreamcast)
Sega broke creative ground when it developed a game that delved into graffiti warfare. Jet Grind Radio was designed by leading graffiti artists like Eric Haze and re-introduced gamers to cel-shading animation, providing the series its trademark comic book-esque look. It proved Sega was in tune with the cultural medium and far ahead of its time with the Dreamcast.
Microsoft took the title and expanded on its awesomeness, making it a launch title for the original Xbox and implementing a series of upgrades, including better graphics and interconnected levels.