Of all the conventions I've attended, the thing that struck me about Blizzcon was Blizzard's commitment to visual splendour. Clearly a lot of money is being spent on making Blizzcon a feats for the eyes. The most jaw-dropping section, for my money, was the incredible Starcraft 2 stage. Now you can watch how it was built.
There were almost 30,000 attendees at Blizzcon, and the stadium set-up for Starcraft? I have no idea how many people it could hold, but it was completely packed out when I saw it (close to the final match) and I was thoroughly blown away by just how detailed and goddamn big the screens were.
Anyway, this video is fascinating. It provides an insight into the work that goes into designing and finally building this kind of set up. This is kinda inspiring to me.