Pick #1: Giant Gonzalez (RIP)
There are wrestlers who have done damage to federations, wrestlers who hurt the product by refusing to put anyone over, wrestlers who were a hazard to everyone else. However, in terms of sheer crapiness, Giant Gonzalez takes the cake. He couldn't wrestle, was a horrible gimmick who wrestled in an outfit that can only be considered a joke. He brought nothing ot the table, other than being really tall. On a personal note, 1993 was the year in my childhood that I started to move away from wrestling. Giant Gonzalez was a big reason why.
Giant Gonzalez was the original Great Khali, only worse.