For me, that would be Secure CRT. I have yet to find a terminal emulator that matches its feature set. If you regularly manage hundreds of machines using various connection protocols (serial and ssh mostly in my case) It’s worth the $$$, and so far there hasn’t been any subscription nonsense. I liked using it at work so much I forked over the dough to have it at home.
None of the free alternatives do everything I need.
I’ll also mention a few iOS apps. One is Sun Surveyor. It’s an AR app that shows you the position of the sun, moon, and galactic center at any given time. The other would have to be Radarscope. It’s a weather radar app, but it’s a really good weather radar app.
Anything that you like can be worth a cost. I prefer FOSS wherever possible, but really don’t mind paying for good stuff. One example is wooshy. This piece of software lets you use the keyboard in macOS for nearly everything, and it is the best use of the accessibility api’s I’ve ever seen. There are similar things but this software is unparalleled in my view.