I'm going to buy a new hd soon. I'm going to leave 5 gigs on it to try and test different distros. I'm looking for interesting ones. They don't need to be easy to install etc. Just interesting.
There're so many different distros, so it's hard to try them all.
How do you think, which ones should I try?

lrs , gentoo and of course Slackware (<- my favourite distro )

s.

It depends on what you're looking to try out. If you're just looking for something completely different, try OpenBSD or FreeBSD. If you're looking for a server environment, you might try slackware or debian or stampede linux.

If you're looking at a desktop, maybe suse.

Really, a distro is only as interesting as the stuff that comes with it. I'd say go for an LFS so you can make it interesting!

I'm going to test differnet distros to look how does Linux look now. I use my Mandrakes, Slack and Debian, but they does not look like when they were installed. I've configured them and changed really much. That's why I don't know, in fact, what do modern distros give to a newcommer. That's what I'd like to know.

Although I think that all the suggestions so far are good ones, (I like the *BSD suggestion especially), to answer your question better we need to know what sort of differences would you would find "interesting".

For example, if you are just looking for different GUI experiences, just try different window managers and different themes (for the ones that take them). Note that the same Window Manager will look pretty much the same on top of any OS (even *BSD). Try some nicely configured versions of Enlightenment, or WindowMaker. Enlightenment has some real "creepy" themes.

If you are looking for a completely different install experience, then then the LFS, Gentoo suggestions are good. I've noticed that nobody had mentioned the Caldera camp, or better yet the related Lycrois/Desktop project, these seem (to me anyway) to have a more nicely polished installer than usual, even though it often doesn't get the job done any better. Another one to watch is Lindows (not out yet) which "promises" to have nicely integrated "wine" and some custom configuration utilities that will make running Windows apps on Linux painless (we'll see!).

Maybe you would like to try a specialized distro, like the many router/firewall projects, some mini-distro's like Peanut or Vector, or some of those that boot entirely on a CDROM and manage to be surprisingly functional, or for a really whacked out mini distro, just try to figure out how muLinux manages to do what it does with just a few floppies! Of course most of these won't fill your hard drive unless you try them all at the same time!

Hopefully a usable highly configurable/customizable OS that is open source, completely free from control of any one entity. The success of this idea is really the most interesting thing of all. Just ask Microsoft who can't seem to figure out how to successfully fight it.

I'm searching for something for home use, nothing specialized (that's what I configure manually). I'm looking for something you'd recommend for someone not familiar with Linux (but not Manrake, RedHat etc, something less known).

To compair distors:

http://distrowatch.com/

this will hopefully help you as much has it has helped me....

Why not Mandrake, RedHat, etc? Is just because your are a "been their, done that" person, or are they lacking something you desire?

Here are some others to try:

SuSe: It's after basically the same kind of user that Mandrake is after, but does things a little different. It is the only one in this list that is a full blown (huge in fact) distro that can do anything.

Lycoris: (formally Redmond Linux), Based on Caldara, but is modified for Desktop use only. The docs and installer additions are NICE. The installer but gives you no choices, which is good for someone unfamiliar with Linux and therefore wouldn't know what to choose anyway. Like Caldera, it only gives a well configured KDE GUI So only install it on high horsepower machines.

Peanut-Linux: This is a stripped down, Mini version of Slackware, meant for desktop use only. It has no compilers, excessive server software or excessive utilities. For an oddball mini-distro, it is well configured and kept very up to date. If it is missing anything you want, just get it from Slackware. Peanut has a cousin which is called Vector Linux. Vector isn't kept as much up to date, and is typically even more stripped down. The install instructions for both of these is brief but concise. Like their father, Slackware, expect a little manual configuring of config files, probably not good for a newbie install, but once installed, they could be good for a newbie to use.

Xandros: It is a preconfigured Debian for desktop use, but it doesn't exist yet. It claims to be following the philosophy of the now defunct Corel-Linux, which was very nice in its time.

Lindows: It is a version of Xandros but with Wine (Window's API) nicely integrated in. Therefore it will run a lot of Windows software. Like Xandros, it doesn't exist yet. If you like this Wine stuff, but can't wait till Lindows, try Codeweavers "Crossover Office"

Open Office: It's not an OS, but an Office Suit. Add it to a distro that could use one. It is probably the best at reading MS-Office files.

If you are looking for a GUI with no rough edges, it probably doesn't exist yet in the Unix-like world (well, except for the Mac OS-X, but you need to be in love with Apple, or at least Apple thinks you need to be). Too bad BeOS never made it, it was nice in this area, there just wasn't enough apps and support for it, I guess it is just a good example of what happens when you DON'T go open source!!! The current Microsoft OS's still have an overall more polished and consistent GUI. Because the Unix-like command line interface is so powerful, once you learn it, a lot of developers see little personal need for a GUI in the first place. MSDOS was a very primitive OS in comparison; soon any meaningful development HAD to be done through their new graphical Windows OS, which hastened its development.

Don' give up though, things are changing very rapidly in the GNU/Linux world, so if you can't find what you are looking for today, check back next year.

Thanks, all of you. It looks it'll be interesting to test them all
I'm not going to test Mandrake, RedHat, Slackware or Debian, because I know them. I'd like this one to be something different.

If you want something totally different, try Darwin (the core of Mac OS X), from here. They have an x86 port for download (ISO image).

I'd like to stay with Linux.

How do you get Darwin-x86 without being an Apple Developer? In other words, how do you get past the login prompt when you click to download the iso image? Or do I have to steal it off one of those peer-to-peer networks.

I would kind of like to check it out.

If you want something truly different, then build your own distro...try Linux from Scratch:

http://www.linuxfromscratch.org/

It will be your version!

You don't have to do anything of the kind. When it comes up with the login prompt, click cancel. It takes you to a registration site, do the simple (and free) registration, and go back to the download. Enter the username and pw you chose and it starts the download.