I use Skype quite often. It's a useful tool for communicating with others and is a great place to hold group discussions. I find it to be a clean and nice-looking program (especially on Windows 8) and it doesn't consume too much memory, which is always a bonus.
I have noticed that my computer's start-up speed decreases when I set Skype as one of my starting programs, but that can easily be rectified by disabling it. Other than that, there really aren't any issues with Skype. Useful program, cheap, and easy to use.