For me, Google video search, Google books (Internet Archive is good, but doesn’t always have the same stuff), Adobe InDesign (but in the process of learning LaTeX), and Typewise. As for the Google stuff, I liked Whoogle a lot, but almost all their instances seem to have been blocked or shut down. Also, apologies if this is repeating an earlier post.
I’ve tried all of them except Zrythm. In fact, REAPER is my DAW of choice. But while that works on Linux, a lot of the plugins I require do not (or well, I guess it depends on how people define “work”), and REAPER in itself is not FOSS.