The Ultimate Guitar Chord Big Book 2nd Half
This chord encyclopedia is the most comprehensive collection of chords ever published - the mother of all chord books! Every chord type is organized into categories: common voicings, drop two voicings, inversions, listings by highest note in a chord (very useful if you're working on chord-melody style playing) and stretchy chords (any chord which spans 5 or more frets).
You won't have to weed through chord after chord to find what you're looking for -- finding what you want in this book is practically effortless. The book also shows all fingerings and voicings for every chord.