BrinkJ: What I'm generally getting from you all is that I should probably get a couple of HDDs to backup everything. Flash drives and SD cards are okay short-term to move stuff around, but not as a long-term solution.
As i mentioned, it appears that good flash drives (including SD cards) should keep data for years to come, even maybe decade(s)... they are less suitable for usage where you constantly write stuff to them. That's the gist I got by reading the articles about flash media durability.
So if your meaning is mainly to copy some stuff to a new flash drives once and then put it to cupboard for years, apparently flash drives are durable in that. But if your meaning is to update and rewrite those files on those flash drives very often, then the flash drive may wear down even quite fast.
It is just that flash media is relatively costly. A small sized 2.5" 2 terabyte external USB HDD costs something like $70, while a 2 TB USB flash drive costs close to $1500.
BrinkJ: The only concern I have now is the risk of HDDs failing. Replacing them every 5-10 years would definitely help, but it's just a concern I found searching through the old forum posts.
People are usually talking about HDDs which are in active daily use (maybe having also heat problems if they are internal HDDs), and/or when constantly moving them around (where they might be dropped to floor accidentally etc.). They are not specifically talking about writing your files to a HDD and then putting it into storage, that's a different question. No HDDs will not last forever in storage either (it is magnetic media, and it parts will also get worse even without use), but it should be relatively safe. Definitely it is the most cost-effective and easy solution, you can put lots of stuff to them, they are quite fast, and you can easily modify files on them when needed.
Why do you insist on one solution? Why can't you use different tools for different purposes? Say, for long time storage (and to be able to easily update the files when needed), put your GOG games and other personal files you want to keep, to an external USB HDD, and put that to a safe place e.g. your cupboard. Maybe also run rhash or dvdsig scan for them so that you can easily check at any time that the files are still ok on it, nothing has corrupted.
For active use, and as a secondary backup, you can also keep your GOG game installers on e.g. an USB flash drive. Not run the games from there, but to install them from there. Then you already have two local backups of your GOG game installers, and the USB flash drive can be handled more carelessly because it doesn't care if you drop it on the floor accidentally etc.
If any data ever gets corrupted on that flash drive or it stops failing due to having written too many times on it, fine, buy a new (bigger?) flash drive and copy your GOG games back to it from that HDD you have in the storege (in case you don't want to just redownload them from GOG).
So HDD for long time storage, and flash drive for active use. Ps. Do you play games on a laptop, or is it a desktop in one place? I was of course thinking my own situation where I have a (gaming) laptop which I might take with me to other places, so a portable media where my GOG games are is a nice thing to have.
BrinkJ: On another note, I have no interest in running games from a USB flash drive/SD card. That seems like it would put too much strain on the external hardware.
I think the main point with flash drives are, are you constantly going to write to them? Reading stuff from them shouldn't really wear them down much, so you could keep your GOG game installers there, and install them from there. That is reading. Installing the games themselves to flash drive and running them from there... yeah that could cause some constant rewrites, at least if save games are located also on that flash drive.
BrinkJ: I'm used to console gaming where if I buy it on a cartridge the game will practically last forever.
Not really. They physically wear down, both from use, but also the connectors oxidizing etc. If you take some very old 8bit Nintendo cartridge which had been used quite a lot and try to play it now, it might easily fail. Don't you remember all the tips how to try get used NES cartridges working, by blowing air (with your mouth) to the connectors before inserting the cartridge, etc.?
And the main point also is that those old console games are tied to that one cartridge. When that cartridge finally breaks down (which it eventually will), you lose the game. You don't have the same problem with GOG games: if you feel your aging storage media (be it a flash drive, HDD or whatever, doesn't matter) might be starting to fail, you can easily copy all your games to a new fresh media which will last another decade.
I feel you just need to change your way of thinking. Concentrate less on the media itself, it isn't that important because you can copy your GOG files easily around, even having them on several places. The files are what matters, and some way for you to check time to time that they are still ok (rhash, dvdsig etc.).
BrinkJ: EDIT:
I've Googled around a bit. It seems after 4-5 years, hard drives tend to give out. Then again, if I don't use one or two of them for anything but storage, that number could get even better:
Yeah those were talking about a different thing, how long hard drives last under daily constant use. If you write something to an external HDD and put it into your cupboard for storage, that is not constant use.
I guess unconnected HDDs eventually fail too and it might even be the data itself being on a magnetic media) might start getting corrupted over time if it is not completely refreshed (rewritten) every now and then, but it is still a different thing.
I recall once taking a very old PATA hard drive (it was at least 15 years old, could be even 20) which I found in my cupboard. I connected it to my PC with a PATA => USB connector, and it worked fine. Now, I can't be 100% sure all the data on it was still ok (no way to check them all fully), but those files that I could check, were fine. For instance, I had lots of zip or arj compressed files on it, and they all still uncompressed fine.
Naturally, I copied all the files worth saving from that PATA hard drive to my newer hard drives. That's the main point, easily being able to move your DRM-free files to newer media.
Links: You can colour me crazy, but I'm starting to think about getting a paid Crashplan account for second tier backup
Yes, saving to cloud is one option if you have a speedy internet, but it is not like Crashplan will be around forever either. At some point they will most probably also close their business, at which point you need to copy everything from them back to your PC (and possibly to some other online service), unless you already have local copies too.
Also it depends on the size of your archive and your internet speed. If I were to copy e.g. my GOG games to such service... well, I have well over 2 terabytes of GOG games already, and the upload speed of my internet connection is only something like 1.5 Mbits/s (download speed is 10Mbit/s). I guess it would take a damn sweet time for me to upload 2 terabytes of data to such online service.
I've already once been in a situation where our family (meaning also my siblings) kept lots of our personal photos and videos on certain online service (community). At one point we just received an email from them that they are closing their operations, so we needed to hurry to download all our stuff from their servers back to us, if we were not sure if we had local copies (and it was stuff we wanted to keep: yeah not necessarily all photos and videos you have are worth saving, up to you to decide. Some don't keep any, they don't mind that their parents didn't preserve videos from their childhood etc.).