Code named "Hardy Heron," Ubuntu 8.04 will be supported till 2011. Ubuntu LTS releases come out every two years and offer three years of support for the desktop version, five years for servers.
I found Ubuntu very exciting in the early days, but I quickly grew disillusioned with the distro's design choices.
With this being the 20th Anniversary since the start of Ubuntu, let us know in the comments which version you used first. My first release was Ubuntu 8.04 LTS "Hardy Heron"!