In the beginning there was the DOS prompt
To begin with there was a C:\> on my screen - that changed to a mouse cursor (a small white arrow on the screen).
The first one was from a graphical menu system called "windows" (who calls a visual frontend to display information a window?).
Here is a small list of things that I've met since '98
1998-2002 RedHat 5.1 - RedHat 6.x
2001-2003 Debian-SuSE
2003-2007 Gentoo
2007-2009 Kubuntu 8.04-8.10, Fedora 5-12, RHEL 4 and 5, CentOS 4 and 5
2009-2010 Ubuntu 8.10-9.04-9.10
(planning on going back to Gentoo...)