I have a weakness for fringe theories, including Shakespeare authorship questions. This a fascinating book that expresses a theory that is similar to the Earl of Oxford ideas (i.e, that Oxford's life seems much more closely connected to the Shakespeare canon than than William Shakespeare's life does), but puts forth Sir Thomas Sackville as the likely real author. Sackville fits better in various ways - he lived longer than Oxford and so doesn't require a complicated explanation for completion of the later Shakespeare plays; and Sackville was also an innovative poet and dramatist as a young man, before turning to a life of public service (he ended up as Lord Treasurer under both Elizabeth and James).
Shakespeare authorship is a very interesting field now: various plays have been added to the canon by orthodox scholars in recent years, as co-written by Shakespeare. There's now a lot of debate about second-rate versions of many of the plays that were for many years seen as pilfered, unauthorized versions, but are now receiving reconsideration as edited, popularized versions of court productions that the common Londoner might enjoy. Doctor Feldman (a physicist at the Jet Propulsion Lab in California) has an earlier book that postulates that William Shakespeare of Stratford wrote this line of crowd-pleasing plays, plus others that nowadays are known as "the apocryphal plays"?":
