1.Easy program installs

Because much of the software for Linux is open source and free, it can be distributed by pretty much anyone. This has allowed for the development of central storage locations for Linux software. With these central locations have come programs that can quickly retrieve software from them.

Things have gotten to the point now that through a very simple program one can download and install a multitude of programs with a single click of the mouse and an administrative password. This also works in reverse and makes it very easy to uninstall unneeded programs.

In my view, this is the killer feature of Linux distributions like Ubuntu.

2.Automatic updates

Sure, updates to the operating system is a common feature for almost all operating systems. This is not a unique feature of Linux. However, with Linux and it's freely distributed software all the open source software on your computer can be updated very very easily. When a new version of your word processor, music player, e-mail client, or web browser is available one little program can update them all with a single click.

This allows security holes to be sealed that much faster and, as far as the Linux community is concerned, would probably seriously impede the spread of a virus (which is not really an issue at the moment because almost no one is trying to write viruses for the Linux desktop user).

3.Multiple Desktops

Instead of sorting through a bunch of windows piled on top of each other like a playing cards you can have them neatly sorted into groups or "desktops". Switching between these "desktops" is much faster than reshuffling the stack of programs to find the one you are looking for. Sadly the term "desktop" seems to be a little misleading here, because your actual desktop stays the same. This is probably better described as "multiple work spaces".

In almost all of versions of Linux a small area of the screen shows mini versions of your workspaces. This allows you to tell where all your windows are with a glance to the corner of the screen. This mini version of your workspaces come complete with little logos or even detailed images letting you know which programs are which. You can even move your windows by clicking and dragging their mini counterpart to another desktop.

This may seem like a small feature, even something rather gimmicky. However, it makes using the computer a lot easier. Think about how many times that you switch between programs and windows during the day. Even if you only save half a second each time you look for a new window, that can quickly add up to a lot of time saved and frustration avoided. It has gotten to the point where I try to avoid dealing with computers that don't have this feature, any moderately complex task is just annoying without multiple desktops.

Some people try to compensate for a lack of multiple desktops by just buying bigger displays or several displays. This is a rich mans work around. Yet, it is impressively easy to setup six workspaces in Linux, and impressively annoying to setup six displays in any operating system.

I know that OS X is in the process of coming out with something similar in a little less than a year. This is certainly a step in the right direction for them. However, you won't be able to see your workspaces without a zooming expose-like step that, despite its original sexiness, can become annoying really fast and negate the time saving benefit of the workspaces.

4.Stability

Granted this is something OS X does quite well also. However, in my experience Linux is even a little bit more stable than OS X (and WAY more stable than Microsoft Windows). This seems to be largely due to the openness of much of the code used in Linux. Because the code is so accessible it has allowed an amazing amount of people to proof-read it and spot those annoying little bugs that lead to crashes.

5.Security

There are firewall and anti-virus programs for the Linux system that are freely available and installable with a single click. These are truly industrial strength programs, and the ones that are used on many many of the computers that house websites. Yet, for the most part these programs are not needed by a desktop user. The system was designed with security in mind. For example a malicious program can't do anything to almost all of the important system files on your computer without your system password. By simply refusing to supply that password to suspect programs a great many problems are avoided. This permission based system can also prevent one from messing up their own computer by mistake (and prevent guests from changing your system settings when you are not looking).