Ubuntu died out an year and a half back as far as I am concerned.
Try as it may, to look and feel great on the outside, its broken and dead on the inside.
I wish Ubuntu went back to being compatible with Debian and got back its old speed.
Till then, I suggest everyone to use Dream Linux. Its an awesome replacement for ubuntu, and from my test runs, I noticed that its as usable by newbies as ubuntu itself.
And if you want something a touch more advanced, and yet debian based, feeling easy to use but at the same time geekish, but on the graphical side, I recommend Sidux.
These two make great alternatives to Ubuntu, especially because they use the official Debian Repositories. They are also inherently lighter and faster due to the debian backend.
And NOTHING, ABSOLUTELY NOTHING, beats Debian Stable Gnome from being the best for enterprise grade server use. Ubuntu server is easily forgotton compared to this.