-Rikishi being revealed as Austin's attacker. An even bigger mistake was when it turned out Triple H (the most obvious choice to begin with) was really behind it.
-Too many random heel and face turns, particularly in 1999. Seriously, there was at least one turn a month that year.
-Too many random and pointless stables. JOB squad, Oddities, PMS, the Union, and to some extent even the Corporation. though I like its overall concept. The members of the corporation were way too random and they changed too frequently (see previous bullet point).
-Too many world title changes. Again, this applies more specifically to 1999. In that year the belt went Rock, Mankind, Rock, Mankind, Rock, Austin, Undertaker, Austin, Mankind, Triple H, VINCE, Triple H, Big Show, and then less than a week into the year 2000 Triple H won it back.
-The 24/7 rule for the Hardcore title. I like the concept of a Hardcore championship but the 24/7 rule killed the belt.
-Mark Henry with a ******.
-Beaver Cleavage.
-Mae Young giving birth to a hand.
-Chyna as IC champ