Back from holidays, finally able to read the last four chapters, thank you Irregular Scans for doing such a great job!
As for the top 5:
1. The story with that young girl that discovered the number zero but no one cared, so she had a small shrine made is my absolute favourite;
2. That case with the best salesman in the world;
3. Sally was really cute and those words sou (/the author) said towards the end really hit me, shooting up in third place;
4. The one with the bad guy who went on an evil pilgrimage, really cool;
5. The one about an old man's garden, about how it was his treasure and he wanted to show it to his family too.
These are the ones which got stuck in my mind the most, but overall I loved all the chapters in this series, Katou Motohiro is a great author imo.