The Nintendo Entertainment System (1985)

What I am about to say may not be a shock to you, but is crucial to the understanding of the Nintendo Entertainment System:  It is the single most important video game console in the history of the medium.  Everything that we take for granted, even things that the average layperson will not realize, we owe to this grey box.  It brought us into the modern video gaming world, and single-handedly resuscitated the video game market in North America after the crash of 1983.
There was a period spanning two years where nobody in the United States would dare produce, market, or sell a video game.  The business models of Atari and their contemporaries had proven that it could not sustain itself, and an over-saturated market has collapsed on itself.   In Japan, however, video gaming was just as strong as it had always been.  A software company called Nintendo had created their first console, known as the Famicom (short for Family Computer) and had been met with success.  It was 8-bit, the most powerful piece of gaming hardware at the time.  They wanted to expand into the North American market, and to do that, they knew they would have to be clever.
After a serious redesign (pictured above), the Nintendo Entertainment System was ready to hit store shelves by Christmas 1985.  But who would sell it for them?  Nobody wanted to carry video games because of the negative stigma it carried.  So in a brilliant move of marketing, Nintendo sold their machine as a toy.  It came packaged with a copy of Super Mario Bros, and since then almost every Nintendo console has come with a Mario game.  It was, of course, a huge success, and Nintendo was able to hold a monopoly of sorts for six years until the Sega Genesis started to become popular in 1991.
Now monopolies are obviously bad for any healthy market, but if anyone was going to have one, the best option would be Nintendo.  The way they managed to keep it for so long was by maintaining the highest quality product available.  Sega had their Master System out there, but the far more popular NES was where third party developers wanted to publish their games.  Nintendo was smarter than Atari too, since they created a lock-out chip for NES games.  The Nintendo would only play games that were licensed by the company and had this chip installed.  Another tactic Nintendo used for quality control was limiting third party releases to five games a year.
What this created on the NES was a golden age of experimentation and high-quality games.  Since every software developer wanted to make games for Nintendo, the competition was between them to make the best games.  Heading the competition were Konami and Capcom.  Konami had their Castlevania games, space shooters like Gradius and Life Force, and a solid line of sports games.  Capcom had Mega Man, Disney games, and Bionic Commando.  Nintendo themselves produced high-quality first-party titles, which set the bar high for third parties.
The NES library, over its near ten-year life span, contains over one thousand games.  Most of them are terrible, but there is still a huge number of A+ titles, some of these spawning franchises that still exist today.  In the terms of good NES games, there are two categories.  There are the classics, like Super Mario Bros. 3, Mega Man 2, and The Legend of Zelda, which are the most fondly remembered.  The other kind of NES games are the ones that die-hard Nintendo fans like to talk about today, the underrated gems.  These include wonderful but overlooked titles such as The Guardian Legend, Crystalis, and Blaster Master.
Experimentation was a big factor of game development back in those days.  The quest seemed to be for programmers and designers to find the ways to make their games look, sound, and play the best that they could.  Some of these experiments, like The Legend of Zelda, with its non-linear story progression, and emphasis on puzzle solving and item collecting, have aged remarkably well.  Others, like Castlevania 2, with its confusing navigation, failed RPG elements, and lackluster design and aesthetic have aged poorly.
Some of the most influential titles were those that shifted from the straightforward arcade approach and went toward the choose-your-own-adventure style.  I pointed out The Legend of Zelda, but there was also Metroid, which fostered exploration and atmosphere, and Final Fantasy, an intuitive and incredibly customization RPG experience.  Games were no longer quick hunks of action which you could beat in a dedicated hour, but were now full adventures, which could take days, weeks, even months to complete.  Games like Zelda, Final Fantasy, and Dragon Warrior were some of the earliest to include a battery for back-up saves, which is taken completely as a given today.
The NES still lives on in our pop culture.  Anyone can recognize the famous themes from Super Mario Bros., or the line "Thank you Mario!  But our princess is in another castle!"  The movie Scott Pilgrim vs. the World is full of NES references, from the main character's band being called "Sex Bob-ombs" to one of the rival bands known as "The Clash at Demonhead".  Many sound effects and songs were taken directly from Nintendo games.  How many people have held something they've found aloft and hummed the Zelda theme? How many people will point out their frustrations at the Duck Hunt dog?  The NES is the reason I love retro games so much.  These games are still fun to play, and more interesting when you look at their historical influence.