220 Aran Stitches and Patterns: Volume 5 (The Harmony Guides)

This, the Harmony Guides, is a canonical series of stitches and patterns for knitting. It, like the Barbara Walker Treasury series, are essential to knitters who want to move beyond knitting other people's patterns.

I understand that this version of the series is going out of print, to be replaced by a new series that is organized differently. I'll probably buy it too.