The languages I use: C# (primarily WPF and ASP MVC, but Winforms on occasion), Java (JavaFX for GUI, I loathe Swing), PHP (Frameworks mentioned in another post. Big fan of OOP programming in PHP, rather than procedural), Python (Mostly for prototyping, never used it for web development though), and C++ (This is mostly for Windows API programming, doing things such as API Hooking and other fun stuff).
Edit: Which one I prefer depends on the project. Alas! There is no one size fits all.