1. Personal

1. Patrick Collison’s Bookshelf
2. Yudkowsky - Bookshelf
3. Aaron Tucker Reading List - Google Docs
4. Michael Lai Reading List - Google Sheets
5. Misha's Reading List
6. Bret Victor’s Library
7. Jeremy Nixon’s Bookshelf
8. Stephen Wolfram’s Library

2. Institutional

1. Santa Fe Institute Library
2. Andreessen Horowitz Library
3. Topos Library

3. Technical

1. Best Textbooks on Every Subject
2. Juergen Schmidhuber’s Machine Learning Lab Reading List
3. Michael Jordan Reading List
4. Machine Learning Books : MachineLearning
5. Susan Fowler’s Physics Reading List
6. Prof. Sussman's Reading List
7. Quantitative Finance Reading List - QuantStart
8. QuantNet Best-selling Quant Books of 2014 | QuantNet Community
9. Math I Ought to Learn
10. Springer have made a bunch of books available for free, here are the direct links

4. CS Communities

1. Top 30 Books on Amazon Based on Links in Hacker News Comments
2. Mind Bending Hacker News Recommendations
3. resources - What is the single most influential book every programmer should read? - Stack Overflow
4. YC's 2015 Reading List · The Macro
5. Data Science Books | Data Science Weekly

5. Entrepreneurship / Business

1. 9 Beach Reads For Ambitious People | Fast Company | Business + Innovation
2. HN Reads
3. Books Recommended By Venture Capitalists to New Graduates — Medium
4. Bookshelf@work | I found that I have blogged, directly or in… | Flickr - Photo Sharing!

6. Book Recommendation Services

1. Suggest Me A Book
2. Five Best Book Recommendation Services

7. General

1. Most Recommended Reads
2. The Surprising Books That Billionaires, Chess Prodigies, Performance Coaches, and Bestselling Authors Recommend
3. Which book has the most page-for-page wisdom?
4. Summer Reading 2014 | Edge.org
5. Meaningness Rational Systems Curriculum