[This is note to myself, just starting to read economics, based just on quick internet search]
The standard beginning graduate school microeconomics textbook is Microeconomic Theory by Andreu Mas-Colell, Michael D. Whinston, and Jerry R. Green (Oxford University Press).
Regarding macroeconomics, the choice is not so clear. I ended up picking two: The Foundations of Modern Macroeconomics by Ben J. Heijdra and Frederick van der Ploeg (Oxford University Press) and Recursive Macroeconomic Theory by Lars Ljungqvist and Thomas J. Sargent (MIT Press).
At the undergraduage level: Microeconomics by Robert Pindyck and Daniel Rubinfeld and Macroeconomics by N. Gregory Mankiw are popular.
A Guide to Econometrics by Peter Kennedy (Wiley – Blackwell) provides a useful orientation to mathematical methods. The Theory of General Economic Equilibrium: A Differentiable Approach by Andreu Mas-Colell (Cambridge University Press) is more advanced.
For general, non-mathematical, introductions I like Basic Economics 3rd Ed: A Common Sense Guide to the Economy by Thomas Sowell, though it’s somewhat longwinded. Russell Roberts’ didactic novel The Price of Everything: A Parable of Possibility and Prosperity and the Friedrich Hayek collection, The Essence of Hayek, are well worth reading.