My background is about third-year mathematics major, including linear algebra and abstract algebra. I'm now studying Atiyah's commutative algebra, but it lacks some concrete, easy examples and it's too brief to fully understand this subject.
In fact I think I don't like algebra, and I want to study other areas. But I heard that algebra is basic, so you need to study to some graduate level(commutative algebra, algebraic geometry, etc..). Is this true?
Anyway, doing only algebra is a little boring. Can you recommend some interesting branch which is suitable for a third-year student based on differential geometry or differential equations? I was interested in those classes.
For commutative algebra texts, see Reference request: introduction to commutative algebra.
For an interesting application of algebra, try reading about differential Galois theory and the existence of elementary solutions for differential equations; see for instance How can you prove that a function has no closed form integral?; my answer there contains a list of papers and books.
Another major use of commutative algebra besides algebraic geometry is number theory. There are many excellents books on algebraic number theory; see a list here.
PS: I assume you have seen fields and Galois theory. If not, then this is definitely the way to go.