These were the WCW World Champions in 2000, I'm keeping "Vacant" in, just because it makes it funnier.
Bret Hart
Vacant
Sid Vicious
Vacant
Kevin Nash
Sid Vicious
Vacant
Jeff Jarrett
DDP
David Arquette
Jeff Jarrett
Ric Flair
Vacant
Jeff Jarrett
Kevin Nash
Ric Flair
Jeff Jarrett
Hulk Hogan*
Vacant
Booker T
Vince Russo
Booker T
Scott Steiner
* That was the infamous Bash at the Beach match where Jarrett laid down for Hogan, and then Vince Russo vacated it, and then made the Booker/Jarrett match
In it's history, the WCW World Heavyweight Championship was vacated 13 times, 9 of those times happened after October 1999