These are some the books that I'm currently reading or have read.

Mathematics

Algebra

• Kenneth Hoffman, Ray Kunze - Linear Algebra

Nice introduction to linear algebra that doesn't spend too much time with explicit basis

• Nathan Jacobson - Basic Algebra 1

Great introductory book to algebra

• Nathan Jacobson - Basic Algebra 2

Nice overview of several topics with various choices of what to check out

• Serge Lang - Algebra

Really I only used it to learn homological algebra lol

• Claudio Procesi - Lie Groups
• Atiyah, MacDonald - Introduction to Commutative Algebra
• Matsumura, Reid - Commutative ring theory
• Hartshorne - Algebraic Geometry

Analysis

• Munkres - Topology (at least till ch 4, ch 5&6 are cool too)

As long as a rough intuition of calculus is there, this book is suitable to read before real analysis

• Walter Rudin - Principles of Mathematical Analysis (till ch 7)

Other than the second chapter which is overly dense with topological definitions, the others are great

• Walter Rudin - Real and Complex Analysis

Nice exposition to measure theory and complex analysis from a more measure theoretic persepctive. Measure theory part (ch 1-9) is great as an intro and the complex analysis is good after you know the basics.

• Walter Rudin - Functional analysis
• Klenke - Probability Theory: A Comprehensive Course
• Miranda - Algebraic curves and Riemann surfaces

Topology

• Lee - Introduction to Smooth Manifolds
• Joseph J. Rotman - An Introduction to Algebraic Topology
• Bredon - Topology and geometry
• Tammo tom Dieck - Algebraic Topology
• Martelli - An Introduction to Geometric Topology

Number Theory

• Neukirch - Algebraic Number Theory

First two chapters are quite nice, tho some commutative algebra experience would really help with going through the content, third chapter is cute while the class field therory is a rather unique approach that may not be the best, but still rather interesting

• Silverman - Arithematic of Elliptic Curves
• Koblitz - Introduction to Elliptic Curves and Modular Forms
• Diamond, Shurman - A First Course in Modular Forms

Physics

• Goldstein - Classical mechanics

Good book once you are comfortable with writing Lagrangians

• Landau, Lifshitz - The Classical Theory of Fields

I'd highly recommend this book for anyone looking to learn Special Relativity (+ Relativistic Electromagnetism). However the General Relativity section is rather questionable since it just tensor wacking which I don't really like.

• John David Jackson - Classical electrodynamics
• Charles W. Misner, John Archibald Wheeler, Kip Thorne - Gravitation
• R. Shankar - Principles of quantum mechanics
• Steven Weinberg - Quantum theory of fields. Foundations Volume 1