Open source drivers are getting pretty good these days. I haven't had any problem with Intel or AMD hardware.
Intel
I hear the old ones are pretty bad, but my G4500HD does everything I need well. Video acceleration could be better though. There isn't a proprietary driver for Intel either, your only choice is open source. The composited 3D desktop in KDE works great on my laptop which has an Intel chip.
AMD/ATi
Right now the older cards are better supported than the new ones. If you could somehow get an x1800 or something from the same generation that would probably be the best. The r300g driver is getting more development work than r600g. That's not to say r600g is bad, in fact it's great! It's just somewhat behind the driver for the older hardware. AMD has a proprietary driver for the new hardware, but in my experience you want to avoid it; it's pretty bad. The hardware covered by r300g isn't supported by that driver, so the open driver is your only option there. And like the Intel chip I have, my Radeon 4850 runs the composited desktop in KDE well.
At the moment, I wouldn't recommend an HD6000 series. The 6900s have no support at all in the open driver, and the others have basic support. Go for an HD5000 or an HD4000.
Nvidia
They have a really good proprietary driver, but the open driver is struggling along. It's getting better all the time, but Nvidia is doing nothing to help the developers. At least AMD helps out a little bit for their hardware.
The advantage to having an open driver is that it will work out of the box in any distro. If you install Fedora, everything will work including dual screen and 3D. The proprietary ones are painful to setup. Neither of them properly set up my dual screens. It was easier to setup with Nvidia which isn't saying much because the AMD blob was just awful at this. Also, anytime you update the kernel, you have to reinstall the driver. Most distros take care of this if you install the in-repo version, but if you don't it's annoying to boot up one morning and realize you updated the kernel and now X.org doesn't work.
If you aren't planning on playing 3D games, either the Intel or AMD drivers are the best. The AMD driver is more modern than the Intel one, it uses the Gallium3D architecture within Mesa (that's what the g stands for in r600g), but they both get the job done.
Probably the simplest way to weed out the trash would be by the created or last-modified date (you might need to experiment to determine which one's better) - just use the date the system was installed as a starting point.
According to Pareto principle that simple filter will probably get you 80% of the effect you are seeking.
(Of course, you may, or even should, combine this one with the black & white lists you have started to assemble.)
Best Answer
This is referring to the fact that Linux (like all Unix-style systems) exposes most of the resources it manages through objects which look like files:
/dev-style devices,/procand/sysentries... In the context of your quote, this property is mentioned because it allows access permissions to be reasoned about in a consistent fashion.