Article Source TuxArena
Any application needs time to be used and tested enough time in order to make it stable. One of the greatest goals of Debian is stability. It's released when it's ready and applications included in the repositories have enough time to be tested through.
2. Debian offers stable, old stable, testing, *and* sid
Why should this be an advantage? First, because there is a stable release, which will fit both desktops and servers. Since Debian stable releases happen rarely, software can get a little old. So any can get to choose 'testing', which is tagged that way because applications are tested more but they are still usable. Sid is bleeding edge, which means applications get in usually as soon as they are released, so you get the newest software only by installing a testing weekly snapshot and upgrading. Considering the stable and old stable offer software which has been tested and stripped for critical bugs, testing usually proves to be the perfect alternative for a user who wants to use up-to-date tools and applications, which include the latest features.
3. The DFSG
Maybe this doesn't say much just when you see it, but Debian has been around since 1993 and it still is as it was. Although the social contract changed a little over the years, it still retained it's originality. It's open, it's free, it follows the GPL entirely, it respects the community needs.
4. Debian is one of the oldest distributions
Although this doesn't necessarily make you wise, take a look at Debian: it's been up for over 15 years and there are a lot of distributions out there who take and eventually expand Debian's work, take Ubuntu or DSL for example.
5. Very rich documentation
Except for the official documentation, there are hundreds of respectable websites which provide Debian tutorials and general documentation. There is usually no problem which can't be solved in Debian or at least which hasn't somewhere an answer.
6. Many distributions are based on Debian
Debian offers a solid base and a powerful system of managing software. Distributions like Ubuntu and DSL use the APT packaging system, which was invented by Debian for easier management of installed software. In turn, everything user-friendly or useful from Ubuntu will get eventually into Debian.
7. Great community
Being one of the oldest distributions out there, Debian has a strong community. Take the IRC channels, both on Freenode and OFTC, take all the Debian-dedicated forums or the mailing lists, consider that there are gurus out there who worked with Debian for years and they will usually offer support and share knowledge.