Worst botched bump would have to be Mick Foley being chokeslammed through the cage and the chair landing on his face. It knocked out a tooth through his nose, dislocated his shoulder and knocked him completely unconcious. It was even worse than the first fall throught the table. The first, he was more or less in control of his body. He wasnt expecting the cell to give way so he had no way to prepare himself.
Worst Worked Bump, I'd say would be John Cena's FU off the ladder through two tables. That could have gone so wrong if one of the tables didn't break, or Edge caught his leg on the top rope, or if the ladder toppled over. It could have gone so wrong in so many ways and it just looked amazing.
Or there was Kurt Angle's moonsault from the top of the cage. Time seemed to stand still as he flew through the air, and I think absolutely EVERYONE felt it when he hit the mat, with no Chris Benoit underneath him.
Sid breaking his leg and Owen Hart falling to his death, I wouldn't consider as bumps IMO.
