I'm suprised that I found some of Vonnegut's later, less talked about books as enjoyable as some of the classic ones. But I enjoyed Bluebeard, Hocus Pocus and Timequake just as much as Slaughterhouse 5, Cat's Cradle, Mother Night or Breakfast of Champions. 
 Even though this technically isn't the last Vonnegut work, it's obvious that he was thinking of it as his swan song in fiction, and it's a near-perfect farewell.