Seriously, if Ubuntu were a single piece of software, it would top my charts. I don't even use it regularly anymore except on my work Desktop (I run Arch linux on all my personal machines) but the sheer level of "Just Works(tm)" is mind boggling. It quite handily picks up my weird wireless cards and video devices without fuss, and I haven't managed to fully break an Ubuntu installation (mostly dealing with nVidia back in the day, when it was less magical to get working) in a way that I couldn't easily revert.

I realize a lot of that is riding on the Debian team, but Canonical has done some fantastic work just testing the thing out on such a wide variety of configurations. It's the distribution I recommend to any of my friends looking to try Linux out for the first time.