Which Linux is right for you? Of course, the answer to that question depends on you.  I usually point people to Ubuntu as a good first choice.  But now I'm not so sure.  There are some good beginner distros that attempt to make Ubuntu even easier to use. 

Pinguy OS is based on Ubuntu and reminds me a lot of the Mac's OS X interface.  The person who created Pinguy OS interviewed friends and family and based on that info determined what should go into a distro.  For a Linux purist, that means a big download and a lot of preinstalled apps that you may hate.  For a new Linux user, that means everything has been carefully chosen in an effort to make it "just work."

Linux Mint is another distro based on Ubuntu. Like Pinguy OS, Mint tries to take the edge off of a regular Ubuntu installation.  This is a good choice for someone who doesn't like the typical Gnome look of Ubuntu and wants a few things to be preinstalled, like MP3, DVD, and Java support. 

I have to admit, I never fully understood why Mint is so popular.  It doesn't add that much to Ubuntu and tends to stay a few months behind the official Ubuntu release schedule.  If you want to create an easier Ubuntu, why not go whole hog like Pinguy OS did? 

Ubuntu - The ultra-popular "Linux for the rest of us."  Ubuntu started back when Linux was more of a catch-all OS for geeks. If you wanted Linux, you'd download the CDs, install the base system, then install the appropriate apps depending on your needs. If you wanted a Desktop-based (Windows-like) Linux you chose between Gnome and KDE. Want to watch a DVD or listen to MP3s? Install a media player and codecs.  On the other hand if you wanted to run a server, you'd choose not to install the Desktop stuff and go with the software that will run a website, email, FTP, and file server stuff instead.  Depending on what kind of server you were installing...

Ubuntu said that was crazy.  They took what was available and choose Desktop packages.  You could still customize it if you wanted, but the software they included assumed you were a slightly above-average computer user. (You are interested in installing a different OS, after all.)

Now I'd classify Ubuntu as a middle of the road distro.  Install it, if you don't mind tweaking some things and choosing your own software for beyond-the-basics stuff.

What about advanced users?  Not everyone is new to Linux.  What if you're sick of the way Ubuntu deliberately stays a step or two behind the cutting edge?  What if you want to customize everything?  What if you hate the 6-month release cycle and its potential to change multiple tweaks and config file changes you personally added?  That was me 2 years ago. 

I was grateful for the Ubuntu community, the helpful forums, the simple install, etc. But I hated that I didn't have low-level control over stuff.  I could switch things out, but sometimes other parts of the system broke when I did that.  I could tweak config files, but that practically guaranteed that I'd be re-tweaking again in 6 months with the next release. I hated that everything was old.  I knew there was a new kernel that had all kinds of cool stuff in it, but I also knew that I wouldn't see it in Ubuntu for another 6-8 months.

Enter the Arch Linux distro. This has been my distro of choice for the past two years.  I use it on a server, my desktop, my laptop, pretty much anywhere I want a computer with Linux.  To get a feel for Arch, go to their site and read the philosophy.  I like that it's a rolling release.  That means a package gets updated whenever necessary.  There is no waiting for a 6-month release schedule. When something breaks in an update it's easy to roll back that package and ask for help.  Since the package in question was just finalized, the maintainer is intimately familiar with it.  There are also bound to be people with the same problem I'm having.  I've never gone more than a day with a broken package. I just can't say enough good stuff about Arch.  I will offer a bit of warning: Arch is not for new Linux users.  It's for people who want to manage their system and don't mind understanding and changing what's beneath the surface.

All of the above are free.  The first 3 are all easy to try and install with a LiveCD/DVD/USB. As a general rule, any computer that can run Windows XP will run Linux very nicely.