Ubuntu 6.x. First version of Ubuntu I tried installs and works, well by works I mean as well as any other version of Linux.
Ubuntu 7.x requires huge work-arounds to get video to work to get the thing installed, and then requires the same work-arounds every few updates, and won't automatically connect to my wired network.
Ubuntu 8.04 released today, won't even start the installer without throwing "isapnp: checksum for device 1 is not valid (0×89)".
Tried two ISOs from different servers, still no joy. The troubleshooting information on the internet is weak to say the least, with suggestions like turning off hardware acceleration and reducing the RAM to 256MB being unfruitful.
And the fanboys actually want people's grandparents to install this instead of Windows! Are they nuts?