The first thing I remember doing online was using the Yahooligans website in like 2003. I didn't get internet at home until 2005 I think, we got super fast 1mb broadband and then it got upgraded to 2mb for free so we could test it.
I loved the EastEnders dress-up game, my brother and I would walk around the house quoting Dot's classics "Ooh, I say!" "Makes me feel like a woman again!"
I played Club Penguin a lot.
I went on Bebo all the time, I loved making "Skinz" for people and getting paid with the little hearts they could post on your profile.
I can remember the first youtube video I watched, it was a very obese man next to a lake dancing to a Shakira song.