Today, PC system security is paramount. Hackers, viruses, and malware usually target Windows systems, so using Linux moves you off the bull's-eye. Execute from a LiveCD and your system becomes nearly invulnerable; any damage done can be corrected by a simple reboot. That's part of why my current distro of choice is Kanotix 2005-2 LiveCD. I wanted a KDE-based distro for its simple, Windows-like appearance to help the "Windows-only" family members with whom I share the PC. And since we require many applications, we needed a full-featured distro and access to additional applications if necessary.