I was at the first one (though not named WWDC yet) in 1986. In the old days this was the funnest week of the year, as you got to talk with everyone and you learned a lot from the random discussions. I went two years ago and everyone sat/stood in long lines using various devices and no one talked anymore. I think watching the videos is enough now.

That first one BTW had 300 people representing virtually all the Mac developers in the entire world, meeting in a single ballroom at the Fairmont. Nowadays you have 5500 people that barely fit into Moscone West.