Ubuntu is marvellous. I switched from Fedora a few weeks ago, and will never be going back. Like Debian, but with a really pared-down set of best-of-breed applications. Nice empty menus as a result. Gnome is not as tweakable as KDE, but is gorgeous to use and doesn’t crash as much. And you still have all the Debian software repository to call on if you need it. Highly recommended.