1. Roland Deschain The Dark Tower Series
Roland became a gunslinger at the unheard-of age of 14 after being manipulated into taking the "trial of manhood" by Marten Broadcloak, his father's adviser and an incarnation of cross novel antagonist Randall Flagg. While Flagg is Rolands chief enemy, he is merely a minion of the evil Crimson King whom Roland must ultimately defeat in order to preserve the Dark Tower the King wishes to destroy. At the end of the seventh novel, it is revealed that he is trapped in a repetitive reincarnation, his "damnation" for his crimes and killings. Because of the sheer depth and breadth of Rolands travels and trials, coupled with the inter dimensional connections to other King stories and his effect upon them, Deschain becomes the true knot that seems to bind the entire King multi-verse together, making him arguably the greatest and most important protagonist of them all.