I remember
-There was a period in TBC when orcs had bugged shoulder size(2x smaller), and worst of all, it took Blizzard 2-3 months to fix it.
and
-And the best one! instance servers being full, and 40 people jumping through the window of MC to zone in, inevitably falling into the lava, getting "Instance servers are full, try again later" message
was pretty awesome XD