As a fellow frequent tex user, I'm curious at the macros you've written. I've found that I've written very few. I believe it is literally one for multi line commenting, breaking up slides in beamer (like 2x2, 3x2, whatever), and dumb things like section titles for homeworks. Do you have anything that you find particularly useful?
I have written a lot of style files (in plain TeX, I am actually a quite passive LaTeX user) for things like handouts and tests I use in my teaching, including my side job as a flight instructor. Some specialized typesetting tasks, like multicolumn dictionary typesetting (was another side project) took a lot of macro writing, as well. I have also written a number of parsers in TeX for pretty-printing code (I use another great Knuth's invention, literate programming, quite a bit). I am addicted to TeX, I can see it now :)
