Lightboards
because of the pandemic, I build a lightboard at home in order to give my classes (this was inspired by Ivo Vekemans - here's an example of him lecturing).
I recorded three whole classes so far on it, and a bunch of seminar talks. Here's one example: andreghenriques.com/OSUseminar2020.mp4. Overall, I'm very happy with the setup.
Advantages: the result is really beautiful to watch.
Disadvantages: This lightboard essentially uses up a whole room. Also, it's a bit time-consuming to clean the board (if you don't clean it well, it leaves lots of shiny smudges). This makes it essentially impossible to give live talks on it.