I prefer Kubuntu as I like KDE over Gnome.

As for fun, I'd recommend Gentoo, not quite as tasking as LFS but still very involving. I learnt everything I know about linux (some would say that isn't very much ) from installing and using Gentoo.

How are you finding Parallels? It was the first thing I put on my new MbP, certainly good enough for the occaisional jump over to Visio and checking windows builds of my projects. I've also downloaded the beta of the vmware for OSX which certainly works but is running dog slow because debugging is enabled.