Ubunutu is great. Ubuntu is the only linux distro on 1 CD per my experience and it is much more than its size.
I had installad v6.10 earlier. The only problem that I came up was with the ISA Server. My internet guy was using ISA server and the clients needed the ISA server to be able to browse the internet. But, there is no ISA Client for other OS than MS Windows.
Additionally, do check your hardware support with whatever version of linux you want to install.
To be honest, currently i am using my copies of Vista home edition that came shipped with my laptop and it works just great. Except that the fact it does not have RDC
. Unless you do not have a money problem, I would suggest go with Windows, whatever the people say its still the easiest windows.