Several years ago I offered a recommendation for the best book about the Shakespeare authorship controversy. Elizabeth Winkler is not the first to suggest that perhaps Shakespeare was a woman or that there were multiple authors of "Shakespearean" works. What she does do is offer very well-informed presentations of all the candidates, incorporating her own interviews with conventional Stratfordian and modern "heretic" advocates.
The chapters that I found most interesting were the ones presenting the case for Christopher Marlowe as the author of many of the plays. He had all of the necessary intellectual, educational, and social attributes, and in addition was deeply involved in the administration of Queen Elizabeth's governance. Many modern scholars believe Marlowe was a spy for her. The Marlovian theory of Shakespeare authorship notes that his death came after a supposedly drunken brawl which involved two other persons now considered to have been spies for Elizabeth. The supposedly fatal blow was from being stabbed in the eye by a knife - an injury that might have disguised the actual identity of the body, which was examined not by a public coroner, but by one of Elizabeth's appointees. After this public "death" (and the pardon of the supposed murderers!), Marlowe is suspected to have then traveled anonymously to the continent, where he could continue his spying under an assumed identity. Curiously, just 13 days after Marlowe's "death" the first works of "Shakespeare" began appearing. See the links for more details regarding Marlowe as the author - a suggestion that is repellant to "Stratfordians" and unappealing to "Oxfordians," but which is interesting to ponder.