TITLE: What are some good group theory references?
QUESTION [36 upvotes]: I'm curious about what books people use for a group theory reference. I don't currently own a dedicated group theory book, and I think I'd find such a book very helpful in my research. What is your favorite book on group theory? Please tell us why you like it — and what sort of groups it focuses on (finite? discrete? finitely generated? etc.)
(For my part, I'm interested mainly in discrete, finitely generated groups, but I enjoy the "flavor" of general group theory books more than combinatorial group theory books.)

REPLY [3 votes]: The book "Linear Algebraic Groups" by Armand Borel and "Linear Algebraic Groups" by James Humphreys are great (and standard) references for the theory of linear algebraic groups. In both of these books, the structure theory of linear algebraic groups uses some algebraic geometry and representation theory.