I am mainly interested in linear algebra. I enjoy reading loup blanc's, Algebraic Pavel's and Julien's answers. It's a pity that they have either deleted their accounts or entered hiatus. Luckily there are still some active members on this site who often provide interesting answers to linear algebra questions, such as darij grinberg, Mark van Leeuwen, Ben Grossmann and user8675309.

I also love reading the answers by (in random order) Robert Israel, Pete L. Clark, Robin Chapman, Gerald Edgar, Bill Dubuque, Jonas Meyer, J.M., EuYu, N.S., Brian M. Scott, MJD, robjohn, Gerry Myers, rschwieb, Jyrki Lahtonen, Hagen von Eitzen, DonAntonio, Henning Makholm, achille hui and Willie Wong. (I am sure that there are names that I forgot to put on the list.) Many of them are old boys from sci.math. Some are new faces.