Here is my bit:
1. If you want support, support, support, then there is nothing better than Ubuntu. For newbie, support is everything, and you get in quick and fast from ubuntuforums.org (absolute beginner).
2. If you want hardware compatability, then Ubuntu it is. I have a moera HP notebook with an irritating ATI card, and issues with rebooting and acpi support. None of the other distro's really worked for me on this hardware, and when I installed Ubuntu Gutsy, I was in linux heaven. Everything works on this old hag: HP Compaq nw8240 full-house specs.
3. If there are packages that are not in the rep, then you will be guarenteed there is a .deb file waiting for you somewhere and it is specifically designed for the recent Ubuntu; e.g. VirtualBox, Opera, etc.
4. Local mirrors for updates/upgrades...so local cap now is std with TELKOM ISP (after cap). Do all your updates then.
5. Enormous amount of HOWTO's on ubuntuforums.org or ubuntuguide.org
6. extensive user-base
7. cutting edge packages every six months
8. DoC South Africa (Meraka Inst.) uses Ubuntu
9. Just the right amount of packages on default install: no-bloatware like Suse, Mandriva, etc
10. Best of all, a SA'can is helping the FOSS movement
Tah,
S