Bruce Lessels
1 Gotta have it if you paddle in the Northeast
Bruce Lessels did a nice job of augmenting Gabler's original work. This book will replace my dog-eared copy of Gabler's book in a place on honor on the backseat of my car. The extended depth and recent scouting updates on the river included within are great. My only complaint is that the pictures included in the book are not contained on the same pages of the river being reviewed. All-in-all a worthwhile purchase.
2 The most essential reference for the northeastern paddler
If you paddle whitewater in the northeastern United States, or intend to, this should be the first guide you purchase. Bruce has updated and extended Ray Gabler's venerable "New England White Water River Guide", greatly improving on that classic. You can supplement it with volumes of the AMC's state-by-state "river guide" series, which have information on many less interesting rivers, but there's enough here for a lifetime of delightful paddles.