Mine is when I asked my mom (age 11) to buy me Pokemon Silver on release day after school and she said yes. My friends were extremely jealous and I remember being too excited for words about all the new Pokemon and the day/night feature.
It's kind of gaming related but mine is from shortly before Pokemon Gold and Silver came out. I found a strategy guide/book at Wal-Mart that covered everything in the game and not only included Kanto info, which was the biggest surprise to me and my friends, but for some reason it had the Japanese names for all the towns, characters, and Pokemon instead of American. I thought it was one of the coolest thing's I'd ever seen. My biggest regret is I don't know what happened to it.
Nail, it's an albino Namek. Kill it like the rest. - Super Kami Guru