For me, it was PC. My mom used to bring home a Compaq 2670 from her work (Pictured right) and my brother, sister and I would play Wheel of fortune, Jeopardy, and other games I can't remember since it was like 25 years ago.
The first games console I ever played was a Sega Master System. Got it as a gift from one of my fathers brothers that lived in England. At the time there was nowhere in Dublin that you could buy games so we had to make do with the two games that were built into the console. Safari Hunt and Hang-on. I know they were built in because both the cartridge slot and the card slot were empty, but the games still worked. You picked the game by putting in the appropriate controller, light gun for safari hunt & control pad for Hang-on.
I remember I was that green about the whole experience that it took a whole year before I actually figured out that you could actually change gears in Hang-on to go faster. Up to that point I thought it was just a short piece of track and the whole game was supposed to last no more than two minutes. My father was addicted to Safari Hunt. Later on when we got our first NES he got addicted to Super Mario Bros. Hell he would play it more than me and my brother put together. Then when I got my first Playstation he would give me stick about playing too much video games.