Probably today USB interface is near a standard in embedded projects. Probably most of them are based on emulated COM port on computer and need additional driver to be installed. It is always better when things work instantly when you plug your project to PC.
This is a great Open Source project of USB generic Hid device that is based on PIC18F microcontroller and works well on Windows. Actually this is a framework to cover Windows Host side and microcontroller side. By using simple prewritten commands you can virtually do anything with MCU-PC communications. PC side is based on Visual Studio C# class library while MCU firmware has prewritten functions to communicate with Windows – Host application. PIC18F has a built in USB interface, so there is a minimal count of external components to set it working. The information is well documented and there are couple examples to get going. So, no more pain with USB.