Ok, lets see here...
I've always been on the computer, playing some sweet Putt-Putt and other games like that on my mad Windows 94. Then I hit 4th grade, (2003) and it sort of exploded.
2003: Runescape. First online game ever introduced to. This was when Runescape classic was also fairly popular, so game mechanics were still pretty poor. This is also where I got my first "Internet Name" - Blob979.
2004: Pretty much still just Runescape, but was probably introduced to Runehq by now as well - back when it was still really popular.
2005: If I didn't discover it yet, I had discovered Runehq now. My name eventually became Blobeh here due to someone named "Canada, eh?"
2006: Maplestory was introduced to me at this point. From here on out online gaming became pretty dang large in my life. Don't know if I still played Runescape, maybe a little off and on. I still play Runescape every once in a while.
2007: Introduced to Blockland, played around a bit. This was around v7, because I knew that soon after than v8 came out with the original wrench events.
2008: Blockland, Maplestory, maybe some other vidya. Pretty much everything got mixed in here.
2009: Started to play WoW, as well as more short-lived online games. I think this is when I started playing TF2.
2010: Pretty much friggen everything.
2011: Still pretty much everything.
In conclusion:
Major games played: Runescape, Maplestory, WoW, Blockland, Dofus / Dofus Arena, Minions of Mirth, TF2, Draconica, Fly For Fun, Travian, Ragnarok Online, Roblox (Hardly though, seeing how I discovered Blockland before it), Minecraft (Way too friggen popular now), and pretty much a ton more.
I was introduced to Runescape by an old friend in like 3rd grade, then reintroduced by Truce in 4th grade, which is when I really started playing. (Yes, I've knew Truce for quite a while)
I was also introduced to Maplestory by Truce.
I was introduced by a friend to Blockland, who never even bought it, then I introduced it to Truce.
Truce and I pretty much introduced each other to most of the games listed above, so he's fairly similar to my story.