Here are some of my complaints about computer hardware (these complaints map to a lot of goods, especially consumer electronics, so extrapolate as you see fit).
For instance, at a show I attended and helped set up in August 2000, there were several machines for which it was necessary to clear the password in the BIOS. This required taking out the cables (of course) then taking the case off the computer (see below) and moving a small jumper (with pliers, since my bluntskull fingers aren't up to it) from one set of pins to another, reconnecting the peripheral and power cables, restarting the machine, clearing the password, powering down, (don't forget taking off the cables ... again) replacing the jumper in its regular position, replacing the case, and connecting all the wires. Again. Nowhere is this jumper labeled, at least nowhere comprehensible to me. Of several experienced computer people present, only one knew where the jumper was and that it would clear the BIOS, and we all worked for the hardware manufacturer, at least indirectly. The PCB of a typical motherboard is covered with marks which may be useful in manufacturing but which constitute noise to the average user, because they hide the few useful bits on the board. Most of the ports are labelled either not at all or so obscurely that they might as well be unlabeled.
(One solution, and something I advocate generally as well for any complex product, is to store at least the most important documentation in ROM on the motherboard itself, say a PDF of the important jumper locations. Some sort of "Hey, tell me what you know!" command triggered by a connected device, for instance a laptop, could transfer at least that to the puzzled humans.)
Here's my answer to that, though it would require some clever engineering: truncate the rear of the case (imagine a line drawn 5 inches down from the top edge of the case's rear meeting one drawn across top panel 5 inches from the rear. That would give a nice surface (35 square inches) much more easily accessable from nearly any angle.(Ironically, the squashed-together ports and doodads on laptops are actually better in this regard, just because a laptop is generally used directly in front of the user, and can be easily turned around or tilted to any angle for easy inspection / reading of ports and placement of cables.
Whoever thought of a round computer port should be tied up with CAT-5 cable, anyhow. What shape is the most ambiguous possible when 2 planes need to be well-aligned? It's not the square, the hexagon or the triangle: it's the circle! Round! Perfect match at all angles, including all the wrong ones! Round is bad here! No round! And most of the possble angles are wrong. Serial cables are slightly (only slightly) better in the matter of shape, since they at least have a narrow side and a wide side. Even so, the difference is suprisingly tough to ascertain and match with cable end when the port is not in full view in good light. USB ports are a bit better, but those two can be confusing when not in good sight, because an upside down usb cable end is still very close to the right size, but will not fit on until inverted.
Beyond that G3 / G4 case (proprietary to Apple and not OEMed for PCs, though I wish someone would risk a worthier lawsuit than for taste-alike iMac rip-offs), most computer cases are awful. The most you can say is that externally they do a mostly adequate job of hiding the componenets from sensitive eyes. Instead, they substitute for what could at least be an interesting view of the componenets a bland beige, grey, white or black box adorned with useless trim, function-destryong curves, chintzy bevels and nothing whatsoever to recommend them. As noted, they place the ports on the rear of the case, even when it would be feasible to place them to the side, to the top, to the front, or (heck, be crazy!) anywhere at all with a breakout box (the best solution). What I'd like is a breakout box which attaches to the PC in the same manner that a "docking station" attaches to many notebook commputers.
The insides of even otherwise passable cases (that is, ones with little chintz, no outlandish bevel and with panels that are removeable without swearing) usually are plenty to make up for any good the outside may have done. The placement of drives within a case usually involves fits that are too tight for comfort, and plugging in power-supply cables which not only take far more effort than they ought to be seated properly, but which soon wrap themselves (along with the associated data cables) into a Gordian knot no sane person can view without itching for a nice broadsword. Often, these cables bareley reach their destination (from power supply to power socket, or between a drive and its associated slot on the motherboard) even when unhindered. Start adding them together, though, and a logic puzzle of the same breed as "can you fit a penny on this table?" manifests itself. The answer is Maybe -- if you pay special attention to the order you connect things (esp. since data cable access is often blocked for all but a surgeon's hand once you plug in power cables to a drive) and ignore those little creaks and groans of bending metal. I hope you remembered to put in all your memory. Also, you might want to check the poorly written manual to find out which banks you can put that memory in, anyhow.