I am the author of TeX Tutorials on Youtube.
- Xelatex because of the unicode support.
- OS X
I am a supporter of up-votes for good questions (not just good answers).
My favorite package is tikz (and tikz-qtree).
22 Which Unicode fonts are available with grades/optical sizes comparable to Donald Knuth's awesome eight grades in Computer Modern Roman? Jun 3 '13
18 Does LaTeX automatically change fonts when switching between Title, Author, Date, and Body Text or sizes modifiers? Jun 3 '13
14 How to create syntactic trees and align them in LaTeX? Apr 28 '13
14 How would I trace a pixelated graphic for my thesis? May 7 '12
11 How can I use variables (or formatting commands) in a header row of a \pgfplotstable table? Mar 31 '15
11 LaTeX template for resume/curriculum vitae Jul 10 '12