Hey there,

I want to make a network with a centralised linux computer, and I am looking for a linux system which combines speed, security and why not ease of use.
Although that I googled, I am really confused probably because I am not a linux expert, and because there are lots of distros.
Your opinion will be very helpful.

Thank you.

That's kind of like asking, what car is best for me? It depends on what you want to do with it, how much time you have to spend on it, etc. I would recommend Ubuntu or if you are just learning Linux and need a good, all around easy to manage server. The odds are whatever you are wanting to do with it, someone else has done it and you will find blog posts and forum posts to help you accomplish it. If you want more security, you might try CentOS or another SELinux-minded distro (Ubuntu can do SELinux as well but you will find many more CentOS articles and people running SELinux rather than Ubuntu). As for speed, it really depends on what you are doing, often, its more about how you configure the box rather than which distro you choose. I would say try Ubuntu first because it is really easy to get started but realize that there are 100's of options out there.

Here's an excellent comparison of the top 10 distros: http://distrowatch.com/dwres.php?resource=major

A recent LinuxQuestions.org user poll choose Debian as the top server distro.

Fast? Speed depends qwhat you run on top of your linux kernel. The underlying system can be the same but replacing KDE with BlackBox can make all the difference.

Secure? Linux is quite secure inherently It depends under which permissions the processes are run. There are aslo those paranoid-safe distros but does it make the difference for regular user will remain to be seen.

hw-compatible? Linux kernel dictates the majority of the hw-compatibility. There are however distros that add their own custom drivers. I believe that Debian policy is not very friendly on that part due to enforcing free components only. Mint comes into mind as an over-all good distro.

Thank you all for you replies which were really helpful. I just forgot to mention in my previous post that I also want good and fast graphics.
Any more recommendations regarding the graphics will be appreciated.

Thank you a lot.

Misunderstood; thought you were looking to set up a home server.

Any discussion of graphics would have to start with letting us know which graphics card you have.

To give you a reasonable advice we need some extra information from you:
What are your hardware specs (especially CPU, RAM, videocard)?
What exactly is it that you are trying to do? In your first post you speak of a centralized Linux network, which implies that you are searching for a server distribution, in post #5 you speak of fast graphics, but fast graphics is normally not seen in connection with servers.
So please be more specific: What is the role you plan for that computer? Which applications do you intend to run?

Also do you want to use the box for hacking linux (straightforward configuration and minimal amount of obstructions and abstractions) or as a desktop environment with minimum hassle to watch videos dowloaded from the internet (all the codecs and players included etc)