I tested tens of Linux distributions, among which I am going to present a few interesting live distros (Linux variants that can be run from the live CD without being installed on the computer). One or more of these could be very useful not only for Linux users but also for very convinced Windows users, for special occasions like wanting to run a lighter, faster OS on their machines, data recovery or just for playing.
At home I have a collection of tens of Linux live CDs and installation CDs.
Currently I am using Ubuntu 9.04 and Dreamlinux and I also use FreeDOS just for playing DOS games. I also use Dosbox and Wine under Linux.
The advantage of Antix Mepis is that it has a very fast and simple yet easy to use graphical interface and programs can be installed easily, like under Debian and Ubuntu.
The advantages of Ubuntu as far as I saw are that it is easy and comfortable to use, it contains a lot of useful programs and many more can be installed from the repositories with simple commands. There are also many useful freeware applications like Opera, Skype, Picasa, Virtualbox, RealBASIC and many more that can be downloaded from the Internet and installed easily.
I tested lots of Linux live CDs, which do not have to be installed on the PC and they can be used just like that, for testing, playing, casualcomputer work and data recovery.
Some Linux live CDs
Slax Linux
It is a live CD, about 200 MB in size which is wonderful for running on older hardware temporarily. It is an excellent data recovery tool.
At bootup there are several options for running Slax. It can be loaded into RAM if there is enough RAM (512 MB at least) thus the CD can be taken out, making the DVD rewriter drive available and such, files can be saved to DVDs by using the K3B DVD burning program included in Slax Linux or the files can be transferred from one Windows partition to another or to an external drive. Excellent for recovering files from a computer with a broken operating system or from a passworded computer.
After bootup double-click on the System icon, then inside this folder there is a "Storage media" folder, then there you will in most cases find two partitions, hda1, which is the C Windows partition and hda2, which is the D Windows partition. Then you can easily access the drives and copy the files wherever you want, for example from partition C (hda1) to partition D (hda5) or to an external USB drive (most probably seen as sda1 and presented with a USB drive icon). You can also easily access data on the hard disk if you boot Slax on a PC onto which another Linux is installed.
NimbleX
This one works in a way similar to Slax, it has a nicer graphical interface and there are more options at bootup, including the option to load the operating system into RAM. It is slightly more difficult to use than Slax. This Linux distribution was built by a Romanian.
Puppy Linux
This is a small, yet fast and powerful Linux distribution. It was built by Barry Kauler, a genius from Australia. It is easy to use. It is also a live CD which, at bootup, loads itself automatically into RAM if it finds enough RAM (more than 256 MB) and the CD can be taken out, thus making the CD or DVD drive available. The OS moves very fast even on older computers and there is a set of efficient and easy to use programs for connecting to the Internet, for establishing various types of Internet connections.
There are a lot of derivatives of this OS, called 'puplets'. Of these, I found Wnop, Puppy Crypt and Mipup very useful.
Damn Small Linux
This is not only damn small but damn fast also. And it runs on very old computers, I ran it and could really use it on a PC with 64 MB of RAM and a 200 MHz processor. It is slightly more difficult to access partitions on the hard disk or on a USB memory stick, though. A longer description will come soon.
Knoppix Linux
This one is really impressive, it is worth trying and studying. It contains a lot of useful software for Office, Internet etc, it accesses the hard disk automatically and displays the partitions on the desktop so it is easy to see what is on them, wonderful tool for data recovery and casual computer work.
TinyME
http://www.tinymelinux.com/doku.php
This is a PCLinuxOS derivative, which in turn is a Mandriva derivative. TinyME is a small distribution, less than 200 MB in size, it can also be loaded into RAM and it runs very fast. It is also good for having Internet on old computers but it lacks a lot of useful software. It has a beautiful graphical interface.
Anyway, Puppy Linux is much better.
Some Linux distributions recommended for desktop computers
I use Ubuntu: www.ubuntu.com which was derived from Debian www.debian.org
Another one, derived from Redhat, is Fedora http://fedoraproject.org
A good distribution derived from Mandrake and the Brazilian Conectiva is Mandriva: http://www2.mandriva.com
There are some very good Ubuntu derivatives, like Kubuntu (Ubuntu with KDE desktop), Xubuntu (Ubuntu with XFCE desktop, suitable for weaker computers), Linux Mint and Fluxbuntu. I used all of them with no problems
Another good Debian derivative, which works on weaker computers is SimplyMepis: https://www.mepis.org/ there is also a lightweight version, Mepis Antix
http://antix.mepis.org/index.php/Main_Page Another one is Kanotix, based on Debian via Knoppix: http://www.kanotix.com
Another good Debian derivative which I installed yesterday is Dreamlinux. Unfortunately, it is not active now.
I use the XFCE version, although I also installed Gnome, which I find quite fast as compared to Ubuntu's Gnome.
Another good one that I tested, a Redhat derivative is CentOS:
A good Linux distro, also suitable for beginners is PcLinuxOS. However, my surprise with this one is that it cannot be booted on my PC due to graphics problems. On my PC it runs only in a virtual machine http://pclinuxos.com/
Another good Linux distribution, a little more difficult to use and with poorer repositories is OpenSUSE. For installation I recommend to choose neither KDE nor Gnome but other: XFCE desktop environment from the options given for installation. Its XFCE is very good and fast: http://www.opensuse.org/en
With opensuse do not forget to keep the install DVD, some more software can be installed from there !