6 Answers
+ 10
c++ c#
+ 6
c++
+ 5
C++ C# Python
+ 3
C# is a mix of Java and C++, so learing C++ might make it easier to learn C#.
It also depends on what your experience level is. I personally learned to code in SML and Java when I first started.
+ 3
C, C++, C#, python. I have have used C for programming microcontrollers, C# for windows application development and python for algorithms, computer vision and AI. All the languages are useful depending on what hardware/software you have and what your intended use is.
+ 1
C++ then C#, Snakes are scary so save python for last