This question is too broad honestly. Let's say I told you C# was my favorite language to program in... Well, that wouldn't be true if I was building a database software which needed the low-level management and control of C. Likewise, C wouldn't be my favorite choice to write a quick script to perform static analysis on a codebase...
It depends entirely on what the project is and what needs to be done. Are we talking my favorite syntax? My favorite language to get things done quick? My favorite language for web development? These questions all matter immensely.