On October 29, 1988, Sega released the 16-bit "Mega Drive" (aka Genesis) in Japan, in an effort to get a jump on the 8-bit Nintendo Entertainment System and compete with NEC's TurboGrafx-16, which was released a year earlier.
Sega Genesis turned 20 this week
While Super Nintendo would eventually overcome the Genesis in terms of global sales, Sega's second console was significant in that it introduced players to mature content (think Mortal Kombat, the "non-sweat" version) and greater irreverence in video games. It also started the fiercely competitive "console wars" that continue today between Nintendo, Sony, and Microsoft.
The Genesis would go on to sell 29 million units worldwide, enjoying exceptional success in both Europe and Brazil and moderate success in the U.S. and Japan. It would be Sega's most successful console before the company threw in the towel as a hardware maker in 2002.
Notable games for the Genesis include Sonic the Hedgehog, Streets of Rage 2, Road Rash, Shining Force II, Flashback, Madden, and a whole bunch more. Here's looking at you, old friend.