1 – Free (and pretty good)
2 – It’s HUGE
Its clearly the most used linux distro. According to Wikipedia, Ubuntu passed 100 million users in April 2009 and many vendors started selling computers with Ubuntu pre-installed:
A number of vendors offer computers with Ubuntu pre-installed, including Dell, Tesco, OP3, Gliese IT, System76, and the South African company Bravium Computers.
3 – Many resources
It is very easy to find help for Ubuntu. A quick search in Amazon listed 800+ books about Ubuntu. There’s an official wiki with loads of FAQs, guides and manuals all organized in a practical and reachable way. If that still haven’t solved your issues there is the “unofficial” forum with over 7.5 million posts.
4 – Stable
Blue screen of death? Memory dump ? Frozen screen? Unacceptable memory leaks? Need to reboot it once in a while? Ubuntu has nothing to do with that son. I’ve seen reports of up-times as far as 2 years and the system kept smooth.
5 – Secure
Open source is more secure than closed source applications for many reasons. More people can detect and fix bugs on open-source software than in closed-source. Even the Whitehouse and the US Departament of Defense have realized that. Also Linux protects system critical resources without annoying the user.
6 – Commercial support
7 – Faster
Doesn’t need to be reinstalled every now and then to keep running smooth since there is no registry. There’s no DLL hell and no viruses. It also uses less hardware resources.
Ironically like I said bellow on the Wine topic, some Windows games ran faster on Ubuntu for me. You can see a very good benchmark between Ubuntu and Windows on tuxradar.com’s article.
8 – Disk space
Ubuntu vs Windows comparing disk space usage. Altough Ubuntu uses way less disk space, it has more hardware support and comes with Office installed. Image source: tuxradar.com.
9 – No registry
With Ubuntu you don’t get that geek registry which is a big exposure of the system, a mess of system and user software configurations mixed forming a SPOF.
10 – Office for $679.95 Free!
It comes with the free OpenOffice suite which can also open and save in Microsoft Office format.
Edit: As noted by Shady, OpenOffice is not yet a full alternative to Microsoft Office. Although OpenOffice has 80% of the most important functionalities that any office suite, it can be very frustrating if you need anything from those 20% of advanced functionalities. I hope it catches up with but only time will tell.
11 – Battery efficient
Ubuntu can be very energy efficient if properly configured.
12 – Philosophy
1. Every computer user should have the freedom to download, run, copy, distribute, study, share, change and improve their software for any purpose, without paying licensing fees.
2. Every computer user should be able to use their software in the language of their choice.
3. Every computer user should be given every opportunity to use software, even if they work under a disability.
13 – Great repository
As a child of Debian, Ubuntu inherited a very special power: it’s package system. APT works seamlessly with the whole system to keep it updated and offer a vast list of software to be installed.
With the addition of Synaptic things got even easier. And now the final blow: Ubuntu app store which is a hub for commercial and free software on Ubuntu. Enabling users to install apps with the click of a mouse, be it paid or free.
14 – Just works
Ubuntu offer better hardware support than Windows and MacOS and uses less resources to run. Add the fact that it can boot without installing and comes with a free Office suite and you’ll see that in most of the cases it Just Works.
15 – Easy and fast installation
Ubuntu installs faster with less clicks. It recognizes and respects other operating systems and try to keep them working side by side. Ubuntu 9.10 even prompts users to import user data and settings from other operating systems that where detected during install.