I use fedora core2 on my laptop because it has a modern X windows server and the support from online repositories using Yum and Apt.
Basicly with one command I can download and install any program that I want and have the dependances and configuration taken care of automaticly.
See here
Read the "ReposityMixingProblems" and understand that I use third party repositories in addition to the official mirrors.
3rd party ones include
ATrpms,
Dag, and
Freshrpms, eventually probably
NewRPMS
With other RPM-based distros you can get the same type of thing going, but it's not nearly as extensive as Fedora's support.
Using 3rd party repositories can cause issues and on average are not as high quality and well tested as the ones you get officially thru Fedora.
For my main desktop I use Debian and have been for a long time and will continue to use it for the forseeable future. My laptop has a crappy onboard video card that requires the newest bugfixes and workarounds I can get. #!@#!!
But Fedora makes it worth it.
That's why I like Fedora over Mandrake or Suse. No googling for some obscure and possibly crappily made RPMs for me!
Redhat is now a completely commercial OS. Fedora is the free version of it, Redhat 10 is DEAD DEAD DEAD. It's not officially supported anymore by Redhat. It's gone the way of the Dodo bird and Windows 98. However you can still get community based support for it from
The fedora legacy project.
Remember that older Linux versions are RIPE targets for crackers. Win98 may make a good spam proxy, but Linux is 1000x times more usefull. Without being up-to-date your asking for it.
It's immune from virusses and worms but security is still a issue. Once a cracker gets in the reliability of the OS is now against you. In Windows it crashes so easily if your not a perfect programmer your going to have constant issues. So any unusual software or usage gets spotted because it screws up your computer. With Linux if a cracker gets root he can make it so it can run complex cracker applications run under your nose and you wouldn't notice.
So be paranoid.
Other popular linux distros are:
Debian (i use this for my desktop. It's UBER Apt is the basis for all things great and wonderfull)
Slackware (no frills, most Unix like)
Gentoo (compile from source, heavily customizable. Portage)
ASP Linux (popular in soviet block, ex-USSR countries)
TurboLinux (popular in China and other asian countries. Designed specificly for enterprise markets, like Redhat. Forms the basis for China's infrastructure)
Red Flag (Official Chinese distro, most popular one in China.)
Mandrake (From france, similar to Redhat/Fedora)
Suse (Originally German, bought out by Novell to replace Netware)
Connectiva (Commercial brazillian Linux. Supports Spanish, English, Portug(ese? al?))
Connectiva, Fedora, Mandrake, TurboLinux, Suse, (and a couple others) are all based directly off of Redhat. Mandrake used to be considured a Redhat clone. As time goes on they get a little bit more different, but they are trying to standardize Linux.
Other distros are much more individualistic.
edit:
Check out
distrowatch for more details
People sometimes critize linux for having several hundred different distros. However you have to keep in mind that many of them are designed for specific markets and specific usages. Some are language specific, others are special purpose like Knoppix live CD or distros designed for creating routers. Some are purely accademic and are created specificly by colleges for coursework. Many are just ego projects, a guy creates one for a hobby and his freinds install it and they screw around with it together.
Improvements will make it back up to the distros they are based off of, and failures and mistakes die.
So it's a weakness because of the fracturing, but it's also a strength.