https://www.gamespot.com/articles/looking-back-at-e3s-history/1100-6458998/

E3 may not be the biggest video game trade show in terms of size and attendance, but it is far and away the year's most anticipated. The annual gaming showcase takes place in Los Angeles every June and has been home to some of the biggest and most exciting gaming news, from console reveals to tons of surprise game announcements (not to mention plenty of often-unintentional hilarity).

The Electronic Entertainment Expo has been around for more than two decades now, and in that time it has solidified itself as the preeminent video game trade show. Every major developer and publisher typically reserves its biggest reveals for E3; Sony announced the price and release date of the original PlayStation during the first-ever E3, and Microsoft unveiled its debut home console, the original Xbox, a few years later at the event. E3 is also where Nintendo dropped the very first trailer for The Legend of Zelda: Twilight Princess, causing an entire theater to erupt in cheers.