I will add more books with reviews soon. Keep checking for updates.

Basic Physics:

Principles of Physics- by Resnik and Halliday
Feynman Lectures on Physics- by Richard Feynman
(also available for free online as a website)

Mathematics:

Advanced Engineering Mathematics-by Erwin Kreyszig

Electrodynamics:

Introduction to Electrodynamics- David J.Griffiths

Quantum Mechanics:

Concepts of Modern Physics- Arthur Besier
Introduction to Quantum Physics- David J.Griffiths

Classical Mechanics:

Classical Mechanics- Goldstein
Mechanics-Course of Theoretical Physics Vol. 1- Landau
(old edition available at archive.org)

Nanotechnology:

Nanostructures and Nanomaterials -Cao

Astronomy and Astrophysics:

e-book Library of IIAP

Free Astronomy textbooks online (some of the links may not work)

Particle Physics and the Standard Model:

Introduction to Elementary Particles-David J.Griffiths
Let’s have a cup of coffee with the Standard Model of particle physics

Relativity:

A first course in general relativity-Schutz

Other:

A road to Reality- Roger Penrose
(Apt for general as well as advanced level, this book has it all.)

A brief History of Time-Stephen Hawking
(He needs no introduction, the book is a gem)