Speaking of indestructible cases, PAL Mega Drive cases would pretty much fit into that category as well.
The old cardboard UK SNES game boxes were never great ... I always used to find them looking tatty after about a week!
Agreed on US 3DO/Sega CD. Especially Sega CD since those cheap plastic boxes would crack and loose their junction, at least you can unfold the 3DO cardbord back in to shape. But I also hate the double CD boxes that came out in EU for Sega CD & 3DO, while most games only contained 1 cd, you had space for 4.
I hate the Nintendo NES, SNES, N64 and GameBoy boxes because they get damaged so easily and it's hard to find NES and original GameBoy boxes in mint condition. Also MSX cases the plastic cover always seems to be warped. I don't really have problems with the size of game cases, just get a shelf to fit them.
(yet) another vote for PAL Dreamcast cases - I agree, they looked pretty smart, but opening them is a nightmare and they break too easily as a result. Weak design.
Actually I've had a few for a number of years and they're in pretty good condition, couple marks or bumps here and there, but intact
When I bought a new game back in the cardboard days, I put the box in another box with all my other boxes. Then stash that away somewhere safe. All our N64 and GB boxes are still sexy.
By far the worst cases I have seen are the Warner Bros "Snapper" cases, like this: http://3.bp.blogspot.com/_ITZ1KLIppt0/S1JfDXvRWBI/AAAAAAAABJY/Urjl7usz_VM/s320/snapper2.jpg I have both a Police Academy box set and a copy of The Dish (imported to Australia from USA) that came in those awful cases. My other vote goes to PC game boxes. No reason why PC games cant follow, say, 360 boxes and move to standard sized plastic containers for most games with boxes only for things that need more than just a DVD and standard manual.
American Saturn cases are the worst I've had to deal with. They're bulky, yet flimsy. There's also more than enough room for the discs to fall off of their spindle and get scratched. If only we had the 2nd-gen European cases.. :/
Yet another vote for PAL Saturn cases, they're a terrible design. The card covers come loose, the spine bends down the middle making the cases floppy and the disc holders are always broken. Even the plastic EA Saturn cases bug me as they are a real tight fit on my shelves because of the hanger! PAL Dreamcast too are terrible, at least you can change your artwork and stuff into a decent condition case if yours gets damaged unlike the Satrurn cases though. The multiple disc cases are the worst, they always seem to be buggered. As for indestructible cases, I'll go with GX4000. Those things are solid, and enormous too considering the tiny carts and manuals they contain!
Just thought of another one...plastic cases for C64 cassette games that aren't just regular cassette cases. Some of them have hinges that are real easy to break, and you can't easily swap the case unless you have another game in better condition.