Not sure I could pick something as I've done some pretty rad things especially this year.
2 easiest I can think of because they were so recent are
-Mixing at Australia's Big Day Out on a huge stage with a few hundred people all watching the band I work for.
-Working for A Perfect Circle and Puscifer for 3 days and the Highlight being Brisbane, Soundwave Festival.
So many things happened that the next day had me casually smiling all day like watching Metallica with Mike from Shai Hulud looking down on thousands of people and remembering that a few hours earlier I was on that Main stage, standing in front of close to the same number of people working for A Perfect Circle. And other little things like having Corey Taylor randomly chat with me briefly or Seeing Lars or James Hetfield stand next to me whilst watching bands.
but I can't probably pick a specific moment in life. I love nearly everything I do.