C# is my favorite language because is relatively easy to write something without having to write a lot and there's relatively little boiler plate and ceremony.
On top of its imperative foundations there were added some functional capabilities that are integrated very well.
What is als likeable is there are a ton of learning materials for those who are interested, a ton of libraries and frameworks and the community being helpful.
Also, C# can be used in about every domain, web backend, web fronted, desktop, small utilities, games, mobile and even microcontrollers.
What I dislike about C# is that every file is also an object and I rather like a less OOP approach.
Also, there are features the community asked for years, like algebraic types and even though people working on the language implementation recognized their importance, they still didn't find their way in the language.
My favorite update to C# would be if it doesn't force so much object oriented workflow. Even C++ lets you work in a procedural way.
Another.NET language I like is F# but I didn't invest much time in it because I don't have where to use it for work.
It's a really nice language to use, I'm quite surprised.
https://github.com/roslynpad/roslynpad