I would like to see/learn how solid principles are utilized in a right way in a real projects.
Or there is none?
<shameless plug>
You can have a look at the source code of my project. I've tried to follow the SOLID principles and the recommendations of the Clean Code book. For example following SRP has caused the classes to be very small and focused - the largest classes are only about 200 LOC (when counting whitespace, copyright statements and comments). It's all in Java, but that is close enough to C#, and the principles are anyways the same.
</shameless plug>