I don't think anyone mentioned the UNIX philosophy that continues to be a tradition in 'every' Linux distribution! Linux is a descendant of the long line of UNIX operating systems that stem back from the '70s.
That said, one of my favorite aspects of Linux is the incredible set of user-land utilities that are sure to be there when you install your operating system, such as sed, awk, bash, and the other GNU utilities, etc. I'm in love with bash scripting, and the command-line, which I owe exclusively to Slackware. I use GNOME, and I have some flashy Beryl effects, but the CLI is so incredibly powerful, I can't imagine how I *ever* got by with the strenuous actions necessary to do even the simplest things in Windows. Its text-based, communicate-with-other-programs nature is truly an outstanding design.
Linux, combined with its inherent ease of developing, makes it seem like anything is possible. I know this sounds corny, but I can feel the power in my fingertips. It's opened up a whole new world of open source that I was never aware of while using Windows. Exciting for a budding programmer.
There're a million reasons, but I won't reiterate or continue. No need to because others will in my stead. Oh. And I love GNOME and the flashy Beryl effects.
