Wanting to try out *NIX in general, I then gave the BSDs a try. FreeBSD's hardware detect was so horrible it wouldn't even boot, and NetBSD seemed to not like the way DHCP was configured, or somesuch. OpenBSD installed well and securely, but X configuration was something out of a horror novel.
I'll admit that I'm slightly different from the average windows user, having paid my dues in the good (bad?) old days of DOS 5.0/WindowsFW 3.11, but the text-only boot-floppies install system aside (getting replaced anyways for sarge's release, as I understand it), Debian is just dead-simple to use. Sure, install asks questions that require thought, and I'd like to see more "if you don't know wtf we are saying, answer no" prompts, but in general, it is well thought-out.
I need not sing praises for apt (its benefits are well-known now), except to say that it is truly bulletproof, accounting not only for dependencies, conflicts, etc., but actually dealing with broken-off downloads on a dialup by resuming them -- a godsemnd when trying to update big debian-security packages over a modem.
Lastly: no, it's generally not the newest and shineyest, but everything is just _so_ well tested. While the bug list(s) may *look* impressively long, Woody at least is just as stable in the user-space as Win2k + properly configured apps.
Both Linux and Win2k have fairly stable kernels that don't crash a whole lot now, but in my past (brief) dalliances with SuSE 6.4, at that time, and with that distro, the apps were just bugggy and crashy. Debian's outstanding package maintainers take care of that by making the userspace programs as much of a technical tour-de-force as the kernel-space stuff, thus creating a truly superior experience for a novice user like me.
By creating a truly well-integrated, maintained, and bug-free distro, IMHO Debian contributes significantly to free/open software's cause.