Despite my "meh" reaction to the first three October Daye books, I kept going because a) I'd read other books by Seanan McGuire and knew what she was capable of; and b) The Dresden Files took a few books to find its feet, too, and it's one of my favorite series. In Late Eclipses, that persistence paid off; this is what I knew this series could be the whole time. It does still have some oddly shaky plotting toward the end, but the twists and reveals are so interesting that it didn't matter. 
 I'll be going through these books a lot faster now that I feel the series has hit its stride.