One of the first pieces of software I paid for was 4DOS[0] - such a joy to use and so empowering. No other command-line experience has ever come close (preps lightsaber..;-) Of course, this was a long time ago.
There was also Photodex's ProShow Gold[1] - imho, the photoshop of photo2video software. Powerful yet so easy to use (after a day of testing). I bought it because I found that this type of creative work helps me relax, etc... Lots of similar software (I about tried them all over the years) but nothing came close. Worth every penny. Not WINE-friendly (I found after transitioning):-(
Company issued but honorable mention: Azure RP[2] for prototyping, wireframing and planning. This was years ago but I never worked with a piece of software that was able to communicate so much, so quickly to everyone involved in a project. Very powerful at the time. Many competitors in this space today. fyi: Have not touch it in many years - it may be completely different now...
These three really stand out, though I have purchased some others over the years. All three are part of the creative process and produce something at the end (script, video, a prototype) - all of which I find engages me.
In the end (personally) it's about how much software will enrich you. There's also a limit on how much I'm willing to spend (usually under $100).
[0] https://en.wikipedia.org/wiki/4DOS
[1] https://www.photodex.com/proshow/gold
[2] https://www.axure.com/