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).
21 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 would I trace a pixelated graphic for my thesis? may 7 '12
13 How to create syntactic trees and align them in LaTeX? apr 28 '13
11 LaTeX template for resume/curriculum vitae jul 10 '12