April 2nd, 2006. In front of 17, 159 fans crammed into the Allstate Arena in Rosement, Illinois, Rey Mysterio defeated both Kurt Angle and Randy Orton in order to become the World Heavyweight Champion for the first time. As he held the big belt above his head in celebration, Mysterio didnt seem to actually believe what had happened. Truth be told, most of the fans were dumbstruck as well. Despite being considered to be pound-for-pound the best wrestler in the world for much of his career, Rey Mysterios small stature had always proved to be a handicap. Hed delighted WCW fans as part of their incredible Cruiserweight division in the 90s and before that, had been a star in AAA and the original ECW, but he was still considered too small to ever truly get over as anybodys World Champion. Since signing with WWE (after WCW went out of business), hed proven to be just as popular with their fans. However, standing at a miniscule 5,6 and weighing about as much as a stick of candy floss (minus the stick), it seemed unlikely that WWE, the promotion notorious for its love of steroid-addled 6-foot-ten beefsteaks, would ever truly welcome Rey into its upper echelons. ...But welcome him they did. Trained by his uncle, the original Rey Mysterio (the name means King Mystery), Oscar Gutierrez began his career under a number of forgettable monikers. However, when his uncle gifted him with the name and legacy of Rey Mysterio, Jr, it all fell into place... Since that time, Rey Mysterio has easily done as much, if not more, for wrestling than anyone else on this list. Hes helped to re-define wrestlings playbook on more than one occasion, hes kept major companies credible with serious fans and hes been a proud ambassador for his culture, helping WWE cross over with Hispanic audiences in a way that ranks him up there with Eddie Guerrero, Pedro Morales and virtually no one else. Mysterio has challenged and defeated boundaries of height, weight, race and wrestling style and the ability of smaller wrestlers to break through at the top level has a lot to do with Reys success as a WWE main eventer. Today, Mysterio is a three time World Champion, having held the World Heavyweight Championship twice and the WWE Championship once. In addition, unlike Blue Demon, Jushin Liger, Tiger Mask, Ultimo Dragon, or even Santo himself, Rey Mysterio crossed over not only with North American audiences, but with mainstream wrestling fans as well. His appeal doesnt lie in his ethnicity, or even in his streetwise, urban take on the traditional masked lucha gimmick, nor does it rest entirely on his remarkable in-ring talents, gilded reputation or flashy outfits. It doesnt even boil entirely down to his underdog appeal and likeable persona, either. In truth, Mysterio is successful because of all that and much more. He is indefinable, unique and special and that is why we love him.