A fork of Rural Dictionary
One of the few things elegant enough to escape the wrath of Linus Torvalds, dpkg is beautiful, simplistic, and self-contained. It does one thing and just one thing and that thing is installing/uninstalling packages. It works great in pipes, and its the epitome of good UNIX design principles.
I love dpkg except when it doesn't work, so I use aptitude which does a million things and does half of them correctly. Ah the joys of Linux.