Nintendo

Nintendo is a publishing company that publishes many series, including the Super Mario series, The Legend of Zelda series, the Kirby series, and the Metroid series and manufactures consoles such as the GameCube, Wii, Wii U, Nintendo DS, and the Nintendo 3DS. Their mascot is none other than Sonic's rival, Mario.

Console Wars
Nintendo and Sega's rivalry ignited with the fourth console war, where the Nintendo Entertainment System (or NES for short) was competing against the Sega Master System. Nintendo and Sega's rivalry expanded to four different wars. Nintendo and Sega were certainly not alone. During these wars, there were other systems. These include:
 * NES vs. Master System (third generation)
 * SNES vs. Sega Genesis (fourth generation)
 * Nintendo 64 vs. Sega Saturn (fifth generation)
 * Nintendo GameCube vs. Sega Dreamcast (sixth generation)
 * Atari 7800 (8-bit;third generation)
 * TurboGrafx-16 (16-bit; fourth generation)
 * Neo Geo AES (16-bit; fourth generation)
 * 3DO Interactive Multiplayer (32-bit; fifth generation)
 * Atari Jaguar (64-bit; fifth generation)
 * PlayStation (32-bit; fifth generation)
 * Xbox (sixth generation)
 * PlayStation 2 (sixth generation)

Final War
During the sixth generation, the Dreamcast held up against the GameCube, but it did so poorly against the PS2 and never competed against the Xbox. The Dreamcast was eventually discontinued.

Third-Party Company
Sega's next move was announcing that they would not be making consoles anymore, and become a third-party company. Since then, Sega has worked with Nintendo to create many Sonic games on Nintendo systems, including Sonic Advance for the Game Boy Advance and Sonic and the Secret Rings for the Wii.

Crossovers
Sega and Nintendo started working to create crossover games between their mascots, Mario and Sonic. The first game was Mario & Sonic at the Olympic Games for the Wii which featured Mario, Luigi, Peach, Daisy, Bowser, Wario, Waluigi, and Yoshi for Team Mario, and Sonic, Dr. Eggman, Tails, Amy, Knuckles, Shadow and Blaze for Team Sonic. The popular release caused the recent demand for Sonic to be in Super Smash Bros. Brawl to grow, and later on, he was confirmed to be in SSBB, which was also for the Wii. One year later, Sega released Mario & Sonic at the Olympic Winter Games which, again, was for the Wii, which included all the previous characters, with the addition of two new characters for each team: Bowser Jr. and Donkey Kong for Team Mario, and Metal Sonic, and Silver for Team Sonic. Then in 2011, Sega and Nintendo released Mario & Sonic at the London 2012 Olympic Games which once again, was for the Wii and 3DS and had the same characters as Mario & Sonic at the Olympic Winter Games. In 2013, the fourth iteration of the series, Mario & Sonic at the Sochi 2014 Olympic Winter Games was released exclusively for the Wii U once again featuring the same characters. A fifth installment of the series, Mario & Sonic at the Rio 2016 Olympic Games was announced, released for the Wii U and 3DS in 2016. An arcade edition of the game was also announced in Japan. Rouge the Bat, Jet the Hawk, Espio the Chameleon, Wave the Swallow, Sticks the Badger, Zavok, Zazz Diddy Kong, Toad, Rosalina, Dry Bowser, Larry, Wendy and Nabbit are new characters to the game.

Collaboration
Along with Nintendo helping Sega to fund the upcoming Bayonetta 2 for Wii U, Satoru Iwata announced on the second show of Nintendo Direct in 2013 that Nintendo and Sega will be collaborating together to make three Nintendo console exclusive Sonic titles for the Wii U and Nintendo 3DS. One title was confirmed to be Sonic Lost World and the other was the fourth-installment of the Mario & Sonic cross-over, Mario & Sonic at the Sochi 2014 Olympic Winter Games. The final confirmed Nintendo exclusive title is Sonic Boom: Rise of Lyric for the Wii U and Sonic Boom: Shattered Crystal for the Nintendo 3DS. Sonic was also confirmed for Super Smash Bros. for Nintendo 3DS and Wii U. However, Smash Bros. is not part of the three-game deal. Two downloadable levels were released for the Wii U version of Sonic Lost World with both being based on two different Nintendo franchises. The first being Yoshi's Island Zone and the second The Legend of Zelda Zone where Sonic dons Link's tunic in the latter. A Sonic amiibo was released in 2015 which allows a NPC Sonic to join the fight. The amiibo is also compatible with Mario Kart 8, Yoshi's Wooly World, and Super Mario Maker which allows the player to obtain a skin or outfit based on Sonic.

Home

 * Color TV Game
 * Nintendo Entertainment System
 * Super Nintendo Entertainment System
 * Virtual Boy
 * Nintendo 64
 * Nintendo GameCube
 * Wii
 * Wii U

Handheld

 * Game & Watch
 * Game Boy
 * Game Boy Play-It-Loud!
 * Game Boy Pocket
 * Game Boy Light
 * Game Boy Color
 * Game Boy Advance
 * Nintendo DS
 * Nintendo 3DS
 * Nintendo Switch

Amiibo support
Amiibo is a line of NFC figurines made by Nintendo. They communicate with compatible Wii U and 3DS titles. Sonic's own amiibo was released in February 2015. The games that included Sonic with Amiibo support are:
 * Super Smash Bros. for Nintendo 3DS and Wii U: Players can train a "Figure Player" to become a powerful fighter and learn new moves and strategies.
 * Mario Kart 8: Unlocks a Sonic-themed costume for Miis.
 * Super Mario Maker: Unlocks a Sonic-based character for Costume Mario; the character resembles Sonic's 16-bit sprite from the first Sonic the Hedgehog for the Sega Genesis. Sound effects and music are derives from the game, though the "end of level" music is from Sonic the Hedgehog 3 and Knuckles.
 * Yoshi's Woolly World: Unlocks a Sonic-themed pattern for Yarn Yoshi.
 * Mario & Sonic at the Rio 2016 Olympic Games: Unlocks the Super Sonic Mii costume.

Trivia

 * Nintendo had a magazine called Nintendo Power, which notably provided the first looks at Sonic and the Secret Rings, Sonic and the Black Knight, Sonic Colors, Sonic Generations, and Sonic & All-Stars Racing Transformed.
 * Nintendo's and Sega's logos are both the color of their respective mascots, Mario and Sonic.
 * Additionally, both Mario and Sonic sport the colors of red, white and blue.
 * Because of the Super Smash Bros. series, Sonic has met more Nintendo characters than Sega (not counting characters from his own series).
 * In 2 February 2016, Nintendo reported its best selling amiibo of 2015 by region in the investor meeting and along the list, Sonic was placed the fifth on the North American region.