I was always a fan of Kanotix. It’s a Debian-based Linux distribution which forked from the popular live distro Knoppix to offer a solid desktop system.
Somewhere along the line, I messed up an upgrade and moved away. By the time I revisited Kanotix it seemed to have lost impetus. Indeed, the last news items on the site today are from 2006.
I believe there was a split between the lead developers and one of them branched out to help create Sidux. I’ve now got Sidux installed in parallel with Windows Vista and I’m very impressed.
I had some initial glitches with screen resolution and fonts, but once they were sorted I’ve had no problems. It is a fast, attractive desktop which is easy to keep up to date.