I broke it trying to upgrade.
I was in a Christian college back in '06, and heard about Ubuntu in a computer science class. After purchasing a new hard drive (being paranoid about losing my Windows data), I installed Ubuntu 6.06.
When 6.10 came out, I decided to upgrade, and I did it over the school network. Problem was, the linux upgrade had a package called libsexy2 in it which was promptly caught by the internet filter, so the upgrade crashed. Being the paranoid person that I was, I uninstalled the libsexy2 package from my Ubuntu installation.
Without noticing the list of other packages that would be uninstalled, I uninstalled libsexy2, and with it the rest of Gnome. Eventually, I had to re-image my drive because I couldn't apt-get anything (the school network required a login through a web browser).
Since 6.06, I've been running Ubuntu as my main OS, though, and it treats me well.