For me, it was perhaps simple-scan, a very simple and efficient GUI to scan documents. I used it with my Brother printer / scanner and it works like a charm. Especially since I do not scan stuff often, so a program with more complex UI would have the effect that I forget how to use it until the next time.
Microsoft Edge was a recent surprise. It’s surprising both that Microsoft would create it and that any Linux users would run it. Since its Chromium based, there should be no need for developers to test Edge separately.