Interesting books that I come across:
(You can buy one for me if you wish) :-)

• Common Practical Lisp
  Thanks to the authors for making this available online. Bought the book as well.
  
• Calendrical Calculations
  Justin bought me this already! Thanks Justin!
  
• Writing Perl Modules for CPAN
  Thanks to the authors for making this available on the internet
  
• How to Design Programs An Introduction to Computing and Programming
  
• Geometrical Methods of Mathematical Physics
  
• Successful Lisp
  
• Common Lisp: A Gentle Introduction to Symbolic Computation
  
• Uncertainty: Einstein, Heisenberg, Bohr, and the Struggle for the Soul of Science
  
• Warped Passages: Unraveling the Mysteries of the Universe's Hidden Dimensions
  
• The Implementation of the Icon Programming Language
  
• Basic Category Theory for Computer Scientists
  
• Modern Compiler Design
  
• Purely Functional Data Structures
  
• Advanced Topics in Types and Programming Languages
  
• The Haskell School of Expression
  
• Formal Semantics
  
• An Introduction To Lambda Calculi For Computer Scientists
  
• Artificial Intelligence: A Modern Approach
  
• David A. Patterson, John L. Hennessy
  
• Transactional Information Systems: Theory, Algorithms, and the Practice of Concurrency Control
  
• Computer Architecture: A Quantitative Approach
  
• Introduction to the Theory of Computation
  
• A Discipline of Programming
  
• Andrew Tanenbaum
  
• Enumerative Combinatorics: Volume 1
  
• Design Patterns Explained: A New Perspective on Object-Oriented Design
  
• Compiler design in C
  
• The Calculi of Lambda Conversion
  
• The Lambda Calculus (Studies in Logic and the Foundations of Mathematics)
  
• C Interfaces and Implementations
  
• C Programming FAQs : Frequently Asked Questions
  
• Flexible Pattern Matching in Strings
  
• Combinatorial Optimization : Algorithms and Complexity
  
• Concrete Mathematics: A Foundation for Computer Science
  
• Categories for Types
  
• The Lambda Calculus
  
• The Equation that Couldn't Be Solved
  
• Proofs and Types
  
• Semantics of Programming Languages: Structures and Techniques
  
• The Art of Computer Programming
  
• Concepts, Techniques, and Models of Computer Programming
  
• Physics of Finance: Gauge Modelling in Non-Equilibrium Pricing
  
• My Life as a Quant: Reflections on Physics and Finance
  
• The Computational Beauty of Nature
  
• Complexity: Hierarchical Structures and Scaling in Physics
  
• Some Basic Theory for Statistical Inference
  
• Brain, Meaning, Grammar, Evolution
  
• The Statistical Mechanic
  
• Essentials of Programming Languages
  
• Emergence From Chaos to Order by John Holland
  
• The Nature of Statistical Learning Theory
  
• Truth from Trash How Learning Makes Sense
  
• Error and the Growth of Experimental Knowledge
  
• Operational Risk Measurement and Modelling
  
• An Introduction to Computational Learning Theory
  
• Mathematical Logic by Willard Van Orman Quine
  
• Geometry Civilized History, Culture, and Technique
  
• Emmy Noether 1882--1935 by Auguste Dick
  
• Physics from Fisher Information A Unification
  
• The First Moderns Profiles in the Origin of Twentieth-Century Thought
  
• Distress by Greg Egan
  
• Permutation City by Greg Egan
  
• Fragile Objects Soft Matter, Hard Science, and the Thrill of Discovery
  
• The Life and Legacy of G. I. Taylor
  
• Infinitesimal Calculus
  
• Calculus by Michael Spivak
  
• Linear Algebra Done Right
  
• Abstract Algebra and Solution by Radicals
  
• Algebra by Michael Artin
  
• Vector Calculus, Linear Algebra, and Differential Forms: A Unified Approach
  
• Introduction to Topology: Third Edition by Bert Mendelson
  
• Topology (Undergraduate Texts in Mathematics) by K. Jänich
  
• Ordinary Differential Equations by V. I. Arnold
  
• Real Mathematical Analysis by Charles Chapman Pugh
  
• Calculus - Early Transcendentals by Howard Anton
  
• Elementary Differential Equations (4th Edition) by William R. Derrick, Stanley I. Grossman
  
• Partial Differential Equations: An Introduction by Walter A. Strauss
  
• A First Course in Abstract Algebra, Seventh Edition by John B. Fraleigh
  
• Principles of Mathematical Analysis, Third Edition by Walter Rudin
  
• Topology (2nd Edition) by James Munkres
  
• Introduction to Modern Set Theory
  
• Introduction to Mathematical Logic, Fourth Edition by Elliott Mendelson
  
• Complex Analysis by Joseph Bak
  
• Euclidean and non-Euclidean geometries: Development and history by Marvin J Greenberg
  
• Introductory Combinatorics (3rd Edition) by Richard A. Brualdi
  
• Yet Another Introduction to Analysis by Victor Bryant
  
• Metric Spaces by Victor Bryant
  
• Real Variables: With Basic Metric Space Topology by Robert B. Ash
  
• General Theory of Functions and Integration by Angus E. Taylor
  
• Principles of Real Analysis, Third Edition by Charalambos D. Aliprantis
  
• Complex Analysis by Ian Stewart
  
• Visual Complex Analysis by Tristan Needham
  
• Complex Analysis with Applications by Richard A. Silverman
  
• Course of Theoretical Physics : Mechanics
  http://ecx.images-amazon.com/images/I/41HJ4Y8N3ML._BO2,204,203,200_PIsitb-sticker-arrow-click,TopRig
• Introduction to Hilbert Spaces with Applications, Second Edition by Lokenath Debnath
  
• Programming Language Pragmatics
  Bought this already.