The default desktop environment which comes with Ubuntu is known as GNOME which is quite simple and easy to use. But you may want to try out some other desktop environments, like KDE. KDE is quite different to GNOME. You can read about these differences from here.
You may have heard of Kubuntu – which is basically Ubuntu, but instead of GNOME, it comes with KDE. You don’t have to move to Kubuntu just to try KDE. It’s possible to try out KDE even on your Ubuntu installation. There are a number of easy ways to do this.