Algebra

Algebra

1. ★★★☆☆ Intuition, analogies and abstraction
2. ★★★☆☆ Ring theory I: Motivating ring theory, domains with integer-polynomial analogies
3. Ring theory II: Visualizing various domains
4. Group theory I: Presentations and representations
5. Group theory II: Visualizing non-abelianness, normality and group products
6. ★★★☆☆ Galois theory I: Walkthrough of Galois theory
7. Galois theory II: Essence of the Galois correspondence
8. Galois theory III: Polynomials seen more generally
9. Homomorphism theorems and a primer on category theory

Algebraic geometry

1. ★★☆☆☆ Introduction to Algebraic Geometry 
2. Bezout's identity [3]
3. Zariski topology [1][2]
4. Nullstellensatz problem
5. Spectrum; rings seen more generally 

Algebraic number theory

1. ★★☆☆☆ Number theory: Part I
2. Class field theory, reciprocity laws, factorization of ideals
3. Group characters and reciprocity laws
4. Mordell equations
5. p-adic numbers