Debian is a preferred Linux release, which is used primarily on PC's, but a lot of people have begun using it lately as a web server OS too, because of the stability and security it offers. The latter is a direct result the fact that Debian is developed and supported by numerous qualified volunteers worldwide, therefore any patch that is needed to fix some issue is released in a matter of days. The same community will also help with any question or issue which a user may ever experience, since they can be contacted through email using e-mail lists and a competent response will be sent in no more than 15-20 min. The advantage here is that all of your queries will be responded to by the same people who have designed the Operating System itself and they have an in-depth knowledge of how it works. As Debian is free, you will not need to pay any license fees to use it and you'll be able to customize it as much as you want or need. This is valid for both the Operating System and the 30.000+ software packages that are available for it.