I've been a fan of HP for a while now, for a consortium of reasons. They've been active in the GNU/Linux community for quite some time (and are sponsoring LinuxCon 2010, which I will be attending), and recently I've been reminded of why I gravitated towards them in the first place. When I first switched to GNU/Linux, one of the biggest issues I ran into was my old Lexmark printer being completely non-functional. In the interest of fairness I should mention that it's recently come to my attention through multiple sources that Lexmark has begun to step up to the plate on this issue, and for that I praise them.
However at the time, there was no such good-fortune, so I wound up going out and purchasing an HP Deskjet F4200. In a wonderful piece of irony, the installation procedure took about 30min on Vista (believe me, I know) and required multiple reboots. When I plugged it into my then Linux Mint 7 box, it worked out of the box... immediately. Setting it up to be shared took up a whole 30 seconds, and I was truly astonished at how it 'just worked'.
As a student, I need to print a lot, and I can not put enough emphasis on the phrase 'a lot', so a working printer is a necessity. For various reasons, the hp eventually got disconnected due to various OS reinstalls, computer rebuilds, and similar issues, and sat in my closet for a while. Today I wired it up to my Arch x86_64 box, and was again pleasantly surprised at how painless it was.
Now, nothing on Arch ever 'just works', that's almost the point, but the setup was as painless as can be expected. After installing hplip and cups (along with all dependencies of course) via pacman I plugged in the printer via usb, and ran dmesg to make sure it was recognized. It was, so I set about the actual printer configuration. After adding cups to the daemons array in my rc.conf, I stumbled across CUPS' Web-UI, which basically grabbed my hand and walked me through the entire printer setup. The phrase 'ease-of-use' instantly came to mind. You can manage printers, jobs, and pretty much anything else you can think of. I'm going to forward some ports later so I can administer it remotely over the web from wherever I am.
It's becoming more and more apparent that GNU/Linux directly equates to increased functionality.