Personal Development
The Passionate Programmer
Ruby
The Ruby Programming Language - David Flanagan, Yukihiro Matsumoto
Programming Ruby 1.9 - Dave Thomas, Chad Fowler, Andy Hunt
Eloquent Ruby - Russ Olsen
The Well Grounded Rubyist - David A. Black
Design Patterns in Ruby - Russ Olsen
Metaprogramming Ruby - Paolo Perrotta
Refactoring Ruby Edition - Jay Fields, Shane Harvie, Martin Fowler, Kent Beck
Rails:
The Rails 3 Way - Obie Fernandez
Agile Web Development with Rails - Sam Ruby, Dave Thomas, David Heinemeier Hansson
Ruby on Rails 3 Tutorial - Michael Hartl
Beginning Rails 3 - Cloves Carneiro Jr., and Rida Al Barazi
Security on Rails - Ben Poweski, David Raphael
The Rails View - John Athayde, Bruce Williams
Rails Antipatterns - Chad Pytel, Tammer Saleh
XP/TDD/BDD:
The RSpec Book - David Chelimsky, Dave Astels, Aslak Hellesoy, Bryan Helmkamp, Dan North
The Cucumber Book - Matt Wynne, Aslak Hellesoy
Specification By Example - Gojko Adzic
Test-Driven Development by Example - Kent Beck
Extreme Programming Explained - Kent Beck
User Stories Applied - Cohn
Agile Retrospectives - Esther Derby, Diana Larsen
The Agile Samurai - Jonathan Rasmusson
Lean from the Trenches
Design:
Practical Object Orientated Design -Sandi Metz
Domain Driven Design - Eric Evans
Patterns of Enteprise Application Architecture - Martin Fowler
Refactoring - Martin Fowler, Kent Beck
Clean Code - Robert C. Martin
Agile Software Development - Robert C. Martin
Software Craftsmanship - Pete McBreen
UX:
The Design of Everyday Things - Donald A. Norman
Don't Make Me Think - Steve Krug
Rocket Surgery Made Easy
Seductive Interaction Design
Business/General:
The Lean Startup - Eric Ries
ReWork - Jason Fried and DHH
Product Development Flow -Reinertsen
Psychology / Behaviour:
Moonwalking with Einstein: The Art and Science of Remembering Everything - Joshua Foer
Thinking, Fast and Slow - Daniel Kahneman
The Power of Habit - Charles Duhigg
Influence: The Psychology of Persuasion - Robert B. Cialdini
Drive: The Surprising Truth About What Motivates Us - Daniel Pink