I've now finished rewatching Hyouka. This is a really good series about Eru Chitandra, a girl with an insatiable curiosity and seemingly boundless energy and Houtarou Oreki, the guy she harasses to solve the mysteries for her who would rather live a quiet peaceful life. But once Eru utters the phrase "I'm Curious" no one is getting any peace until she has the answers!
The artwork and animation is excellent and the storyline is well paced with the various mysteries well constructed. The characters are also well developed and the interaction between them is very good and provides quite a bit of subtle humour.