Launched in 2000 and priced at $300 per unit, the PS2 became the fastest-selling console of all time, quickly overshadowed 1999's Sega Dreamcast, and later it outsold two challengers launched in 2001, the Nintendo GameCube and the Microsoft Xbox. Even today, slimmed-down PS2 units sell in greater numbers each month than Xbox 360, Nintendo Wii or PlayStation 3 consoles. Only the Nintendo DS handheld comes close to the PS2 in the size of its user base. Crucial to the PS2's original success were its built-in DVD (foreshadowing the inclusion of the Sony-backed Blu-ray format in the PS3) and its ability to play games designed for the original PlayStation and make them look better. Among the noteworthy add-ons available for the PlayStation 2s were a DVD remote, a hard disk, a mouse, a keyboard, a Linux kit, a headset/microphone, an Eye Toy camera, and game-specific peripherals such as the Singstar microphone and the Guitar Hero guitar. In 2005, PC World ranked the PlayStation 2 in 11th place on our list of the 50 greatest gadgets of the past 50 years.

After supplying the operating system for Sega's Dreamcast console, Microsoft ventured directly into the console race -- with the PlayStation 2 squarely in its sights. Unlike the PS2, the $300 Xbox boasted a built-in 8GB hard drive and was broadband-ready out of the box (the Xbox Live Online gaming service launched a year later). The powerful Xbox had a PC-like design and used a modified 733-MHz Pentium III processor. One of its launch titles, "Halo: Combat Evolved," emerged as the best-selling game of 2001. Microsoft slowly gained traction with its original Xbox. The company got quicker off the mark, too: In 2005, the original Xbox's successor, the Xbox 360, reached stores a full year before Sony countered with its PlayStation 3 and Nintendo unveiled its Wii.

Nintendo versus Sega

What's so great about Nintendo?

After a North American release through Atari fell through, Nintendo went it alone, unveiling its Nintendo Entertainment System (NES) at the 1985 Consumer Electronics Show (CES). Nintendo's Mario, the Mario Brothers sibling originally known as Jumpman, is arguably the best-known and most beloved video-game character in history. By 1990, the NES was the best-selling video game console in the United States, thanks to titles like "Super Mario Bros.," "Duck Hunt" (with Zapper gun), "The Legend of Zelda" and "Donkey Kong Jr." In 1989, Nintendo began to lose market share in North America to Sega's 16-bit Genesis console -- a circumstance that Nintendo sought to reverse in 1991 with the release of its own 16-bit console, the Super NES. These two 16-bit rivals were the key combatants in the notorious console wars of that era -- a conflict that stirred more intense schoolyard and media debate than today's Xbox 360 versus PlayStation 3 rivalry. Were you a Mario maniac or a Sonic the Hedgehog kid?

Sega launched its Master System in the United States only a few months after Nintendo's original NES became widely available. But Nintendo had a trump card to play against Sega: Its strict game developer contracts prohibited developers from releasing any NES game on any other console for two years. Because the NES had emerged as the dominant console, a developer had to decide between maximizing its game's sales and gambling on the success of a new console. This stark choice helped limit the game offerings Sega could muster. In 1989, Sega hit back with its Genesis console (known outside North America as the Mega Drive), the first true 16-bit console. The Genesis pushed the NEC TurboGrafx-16 into obscurity and quickly began eating into sales of Nintendo's original NES. Nintendo took two years to achieve parity on a technical level with the Genesis, via the 16-bit Super NES. Sega's blue-spiked mascot Sonic is a relative newcomer to the video-game scene (born in 1991). Though Sonic is a freedom-loving and independent super-hedgehog (faster than the speed of sound!) who can be counted on to come to the aid of his friends, he can be testy, and doesn't do well in water without a good running start.