1990, so solidly Gen Y. I remember not having internet access, but I don't remember not having a computer at home. Some of my earliest memories involve playing DOS games.
I think 9/11 is a pretty defining moment. I was in 6th grade that year, so I was old enough to understand what was going on but not old enough to really be interested in politics, so I became politically aware in a world with a war on terror and patriot act.