The great Bette Davis would have turned 100 on Saturday, and of course that occasion is being marked in the marketplace. (And by cable’s Turner Classic Movies, which will show 24 hours of highlights from her career.) Two medium-sized boxed sets are being released: Volume 3 of Warner’s Bette Davis Collection, available now, and Fox’s Centenary Celebration Collection (billed on its box simply as The Bette Davis Collection), which comes out Tuesday. The Fox set offers fewer films (five to Warner’s six), but boasts more famous titles — notably, the classic All About Eve, which has already been available on disc (a few of these have) but here gets a full second disc of new bonus features. The set creeps into the mid-to-late period of the actress’s career, when she found herself being cast in menacingly spinsterish roles like The Nanny. The Warner set, on the other hand, highlights Davis’ youth (despite a film titled The Old Maid), in which she won audiences over in melodramas like All This, and Heaven Too. Box sets like these tend to be a bit random in their approach to stars’ histories, since most actors with long careers wound up working for many studios, leaving different companies rights to the films. Fans looking for a more comprehensive picture of Davis’s career might check out last fall’s biography Dark Victory, or Bette Davis: The Performances That Made Her Great, released in paperback about a month ago, which is less a bio than a recap of what the author believes were her best performances.