As a recruiter I look for
C++ for several reasons:
0: Employers ask for
C++ more than C#, and a lot more than Java.
1: It is evidence that you're smart.
C++ is harder than C#
2: It is evidence that you've had a better education, people who do weaker courses do weaker languages, on average.
3: It shows you are a member of the set of people who do things to computers, more than someone who computers do things to. As Daniel rightly says,
C++ allows you to hurt yourself badly which is good if you aren't broken by it.
4:
C++ is the code they have most of their important work in.
5:
C++ is a richer framework in which to express your ideas in code. Fully understand
C++ and you understand very nearly everything in Java, C# , VBA et al.
Some employers will accept C# rather than
C++, in fact some C# employers ask for
C++ when they actually want C#, because on average
C++ programmers are so much better clued up. I've even had that for
Python developers.
2: