#3 NWO overload
The original NWO consisted of three members: Hogan, Hall, and Nash. As time passed, more and more wrestlers began joining the notorious faction and the storyline became ridiculously convoluted.
It was getting hard to keep track of who was with the NWO and who wasn't. WCW tried to cash in on the NWO storyline by adding another faction to the fold, called "NWO Wolfpac", which was an anti-NWO group consisting of babyfaces. Eventually, fans began losing interest and the group that helped WCW in rising to the top ended up being the major reason for its demise.
#2 David Arquette becomes World Champion
WCW crossed the limit with its over the top booking when David Arquette was made WCW World Champion on an episode of Thunder. Arquette was the main star of the movie, "Ready To Rumble" and the win was a sleazy attempt to promote the film.
This was one of the final straws before WCW's ship sank to the bottom.