A Linux distribution, often simply distribution or distro, is a member of the Linux family of Unix-like operating systems comprising the Linux kernel, the non-kernel parts of the GNU operating system, and assorted other software. Here is a list of the GNU/Linux distros recommended by PolishLinux.org. By clicking on specific distro you will get more details about it.
If this is not enough, here are some more links that may be interesting for you:
- Linux Distribution Comparison -- compare two selected distros side-by-side
- Linux Distro Chooser -- answer 10 questions ans see which distros are best for you
- Best Live-CD distros -- diskless Linux overview
- Distrowatch.com -- hundreds of distros to choose from (includes out-dated and unsupported ones)