Isn't it great that the open source world gives you a lot of choices? When it comes to Linux distributions, shortly known as distros, there are hundreds of them.
Once you have selected a distro, you are up against a decision regarding the desktop.
You need to know enough about the pros and cons of these choices so that you can pick the one that is right for you.
Let us briefly revisit the requirements for a successful migration.
You have to meet three requirements before installing Linux on your home PC:

1. You have identified a demonstrable benefit you can gain by migrating to Linux
2. You have done your prep work
3. You have realistic expectations

By following these three steps, you will maximize your chances of success.
However, there is a mind boggling variety of Linux distros available.
Let us try and shortlist the Linux distros based on the following five criteria:

1. Is it backed by a commercial vendor?
2. Is desktop Linux for home a stated focus area for this vendor?
3. Is a retail product available in the form of a CD/DVD?
4. Are branded PC vendors shipping this distro pre-installed?
5. Is paid support available, if needed?

We find that there are only two Linux distros that meet these five qualifications largely - Ubuntu and SUSE Linux.
Ubuntu

• Sponsored by Canonical.
  
• You can download it free, buy it on DVD from Amazon or get a free CD shipped (takes 6 to 10 weeks).
  
• Starter support for Ubuntu Desktop Edition is available for one year at $ 54.
  99 (as of Sept 2009).
  
• Security update is available for 18 months from release.
  

SUSE

• Sponsored by Novell.
  
• You can download it free, buy it on DVD from Amazon.
  
• You can buy a package from Novell consisting of a DVD with printed manual and 90-Day installation support (by phone or e-mail) for $59.
  95 (as of Sept 2009).
  
• Security update is available for 2 years from release.
  

Can I buy Linux pre-installed from a branded PC vendor? Dell offers PCs for the home and home office market pre-installed with Ubuntu Linux.
HP and MSI offer PCs with Novell SUSE Linux Enterprise Desktop pre-installed.
Asus offers notebooks with Xandros Linux pre-installed.
Acer offers notebooks with Linpus Linux.
Can I get Linux pre-installed from another vendor? Zareason, Berkley, CA and System76, Denver, CO sell Ubuntu Linux desktops and laptops.
Which desktop? Though there are other options available, we will restrict our selection to the two leading desktops, namely GNOME and KDE.
GNOME

• GNOME is a very mature and stable desktop.
  
• The GNOME project has well defined human interface guidelines to make the desktop and applications easy to use.
  Most GNOME applications follow these guidelines, resulting in common usability between applications.
  
• GNOME doesn't provide a graphical interface for some of the settings.
  Users will have to use the command line interface for these.
  

KDE

• KDE is also a very mature desktop.
  However, KDE 4 was completely rewritten and so had some issues.
  The recent 4.
  3 version seems to be more stable.
  
• KDE is also better for new users switching from Windows, and relies less on the command line interface.
  
• Unfortunately, KDE does not use Firefox as the default web browser or OpenOffice as the default office suite.
  You will have to install Firefox and OpenOffice  subsequently.
  

If you are planning to use an older machine and just require stability and an uncluttered approach then you can go with GNOME.
However, if you have a newer machine, looking for a desktop closer to Windows and avoid the command line interface, then KDE is your best bet.