Case Closed 38
In this volume, Conan tried to take on the Black Organization, but it nearly turns out worse than he could ever have expected. Then there's a robbery from a home with hina dolls set up, a murder at a wrestling show and a visit from Heiji and Kazuha that gets derailed when they get kidnapped and the kidnappers demand they solve a code.
As usual, the story with the guest stars is the one I prefer, and in this book it's the Heiji and Kazuha story. Partly just because of the misunderstandings going on there, and partly because that they're surprisingly cool with the whole thing. Well, that's not the right way to put it exactly, but their faith in Conan/Mouri trumps everything. Man though... the code in that one had me a little confused about how they worked it out, even after they explained it. O.o
Case Closed 39
In this book, Conan and Heiji join Mouri in investigating a case of arson where everything's not as it seems, the kids are on a camping trip that gets interrupted by a murder and Mouri gets hired by a child star to find his birth mother.
It's hard for me to pick a favorite here, since all three of these are actually really strong, enjoyable tales. All three actually have a bit of emotional resonance - with one of the suspects in the first case, with one of the campers (and with Ai) in the second and with both the child and the mother in the last. I think it's one of my favorite volumes of this series.