My first Gaia event was the Back to School event in 2009 where every time you logged on, you were counted as present and you got items based on how many days you logged on. I actually joined just in time for that event
If that doesn't count, then Halloween 2009 (BOO vs. SIN) was my first event. I kind of liked it, but I didn't like how the Gaians acted during and after the event.
I joined in September 2006, and so the Halloween event happened about a month after I joined. I didn't really participate though, because I didn't understand it completely. The first event I took part in was the 2007 St. Patty's Day Event with the four leaf clover pins and floppy clover hats.
I joined December 1st 2003. Also known as forever ago. sweatdrop
My first gaia event was Gaia's 1st anniversary. in 2004 held at gambino's mansion. Prizes were things like , white Gaia T-shirts in sizes from s to xl, noise maka's paper party hats. As well as a letter from gambino, after the event. I enjoyed it a lot. Things were simpler then.