There are over three hundred Linux distributions that you can choose from. The choices can be overwhelming. There is no agreement as to what is the best linux distro. We know that Linux Ubuntu is the most popular on the desktop and Red Hat Enterprise Linux is the most popular in enterprise settings. But popularity does not equal best fit.
So what is the best linux distro? It depends on your needs and what you are looking for.
1. For newbies:
If you are new to Linux, I suggest you use Linux Mint or PCLinux. These are the most user friendly distributions.
2. Everyday Linux:
If you are looking for a distro that is going to be around a while and is relatively easy to use, then I suggest Fedora or Ubuntu. Fedora is based by Red Hat and Ubuntu is backed by Canonical.
3. Light and fast:
If you have an older system Puppy Linux is the choice for you. It is an amazing distribution for older machines.
4. Server:
CentOS is simply an unbranded and free version of Red Hat Enterprise Linux. Debian is also an excellent choice, being well known for its stability.
5. Music Production:
Ubuntu Studio is the most popular music and recording solution out there.
6. Multimedia :
If you are interested in turning your computer into a multimedia station, Mythbuntu is the distro for you. The learning curve is a little high, but worth it.
7. Power User:
If you really want to learn Linux, then Gentoo or Slackware is the way to go. Slackware just happens to be the oldest Linux distribution still in active development.
8. Netbooks:
If you are think of using Linux on a netbook, EasyPeasy or Jolicloud are both good choices.
9. KDE Desktop:
For those who like the KDE desktop enviroment OpenSUSE or Kubuntu are probably the best.
10. Kids:
If you have kids the best option for them is Edubuntu.
Hope This Helps!