As with any historical period that becomes suddenly popular with readers, a lot of mediocre novels set during the Tudor period have been published. I think that's why readers get really tired of a particular historical period - if one were to read only the really outstanding Tudor-era novels (which are also to one's personal taste), I don't think one would get tired of the Tudors. I thought I was pretty tired of them, myself, until Hilary Mantel came along with Wolf Hall
and now Bring Up the Bodies
. She made them fresh and new again for me. I also really enjoyed Margaret Irwin's trilogy about Elizabeth I (before she became queen), starting with Young Bess
That said, I particularly enjoy a well-written novel set in a time period that is new to me. I've just posted David Maclaine's reviews of Harry Sidebottom's "Warrior of Rome" series (see series review
, which has links to the individual reviews), set during the third-century crisis period of the Roman Empire, which to my knowledge has not been the setting for any other novels. It takes a daring novelist to tackle some of these settings, because publishers generally want "marquee" names that are familiar to readers - Cleopatra, Caesar, Napoleon, Mata Hari - and those familiar historical figures are naturally absent from the unfamiliar settings. Sidebottom has been successful because of his excellent research (he's a classics scholar who also publishes nonfiction) and the you-are-there battle scenes in his novels, which are breathlessly suspenseful. One can't entirely blame publishers for wanting to focus on publishing the novels that will sell best, but it's always nice to see a novelist succeed who writes well about the less trampled settings of history, because we get to read his/her novels!