I've been playing since beta, so the newer players won't understand this, but I got my first purple engram (a primary weapon, and I just knew it was going to be a bad ass scout rifle). I was so excited, got to the tower and went to the Cryptarch to decode it and .... he turned it into a blue auto rifle. It kind of hurt my feelings. edit - I really don't think I've ever been as disappointed in any other RNG moment in this game as I was my first legendary item getting turned into a rare one. And then it kept happening for the next three months or however long it took them to finally fix it.