Earlier today I came across a short article asking the absolute moment that videogames hit mainstream. The answer's probably not the same for everyplace, and the answer's probably not even the same for every person but as somebody who started gaming in the Philippines as early as 1986, I can at least shed some light (from my direction) on the subject.
The first probable time you can say gaming hit the mainstream is with the release, and the subsequent popularity of the Nintendo Family computer (Famicom), peaking sometime in the early to mid 90s. Before this, gaming was restricted to godawful personal computers that required multiple floppies and amazingly confusing jargon to install. For those who bitch about having to copy paste cracks, update software and the like, try having to update your bios and experiment with IRQ/DMA/IO just to get your game to work on DOS with sounds.
No, with the Family computer, anybody with a TV, a system unit, and a game cartridge could operate it. Hell, even my mom played it. Rental gaming centers popped up for the first time too, which was the reason my parents were called by our principal when i was in first grade for cutting classes. For the first time, video games were accessible to those who have the money but don't have the techie knowledge.
The one thing that the NES fever lacked is the idea that it could be for everybody. It was a toy, pure and simple. Adults would have none of it and those few that do, are afraid of talking about it in public, as though it were some sort of weird bedside fetish.
This changed sometime in 1995, when the playstation was released. The PS1 was radically expensive initially, but it was introduced not as a kid's toy, but as an entertainment appliance. Michael Jackson endorsed it. Michael Jordan endorsed it. Superstars endorsed it and not the prepubescent models of Nintendo. The games that came out were not only sophisticated. They were mature. They had blood. Violence was more graphic. The only thing that held back its popularity was its price. At 30,000 pesos a unit, it was not for everybody.
And then something else happened. Sometime when the PS1 units finally started depreciating, piracy came in. Don't get me wrong. Piracy has existed far longer than I have as a gamer, but with the age of CDs, piracy no longer meant having to shell 200 pesos for a 300 peso discount on a cartridge. It meant, in the year 1998, you can buy an entire game for the price of 30 pesos in the middle of a video store (Astrovision, from my experience) inside a mall. At 12k a system unit and 30 pesos a game, adoption exploded. Rental shops were everywhere. Every other classmate had a system unit. Games were swapped with abandon, both old and young.
Videogames was now accessible, and for all ages. At this point I can say that VGs have already hit the mainstream, but there's one more step.
Sometime in the year 2000, in parallel with the playstation's popularity, the PC once again became a popular gaming device of sorts. Game cafes started growing around the country for one big reason: Counterstrike, a first person shooting game. Whereas as recent as 1998 people had to go to Greenhills just to be able to play a decent 30 player game, by 2000, every other mall or college hangout had a cafe that could host a game twice the number of players. Counterstrike, at its very heart, is really the first popular multiplayer game that doesn't just have players alternating in two controllers in front of the TV. It didn't need taking turns. Counterstrike was a game that involved people and in turn, socialized gaming itself.
It did not need investment in buying a console either. Anybody of any age with 40 pesos (it was still expensive at the time) could buy an hour, sit down, learn the game, and play with friends. It became an acceptable alternative to other social activities. Even girls finally got involved (a very rare sight prior to year 2000, to be honest). Tournaments were setup, cliques formed within and outside the game cafes, and people were no longer as afraid of telling other people what they like to do. People recognized videogames, albeit still with some apprehension, but accepted that yes, some people, adults even, consider it as an entertainment. A sport.
That year, I walked into a game cafe one of five in the same mall with my friends, saw college girls playing with guys who looked anything but geeks and spent two hours in Counterstrike playing against them.
It was at that moment that I realized, videogames have finally hit mainstream.