My Current Backup Approach
Although I have used RAID 1 and RAID 10 in the past - even occasionally RAID 0, I am not currently using any of those approaches to maintaining my backups. In fact, I don't even have a RAID setup in my current desktop even though it's perfectly capable of supporting one. I even have a pair of matched hard drives.
Recently, I've switched to using Solid State Drives (SSDs( in place of HDDs. My system boots lightning fast and games load almost too fast. However, when it comes to RAID systems, the cost of SSDs makes raid a bit prohibitive. I have a 256GB SSD and 500 GB SSD and when I bought them, the cost of a pair of 500 GB SSDs like the one I have would have been nearly quadruple what the cost of a pair of 1 TB HDDs. That's not the cast any more as the drive has dropped from nearly $300 when I bought it to $178. That's the quote I got today from Newegg, and though it's a sale price, it's not much off the regular price. I probably could set up a RAID system if I wanted to, now, but I'm happy with the solution I have.
I have switched to using CrashPlan from Code42.com, which is backup software that lets me pick the files and folders I want to back up and copies those to another system. CrashPlan is available as both a free version and a subscription version. The free version of the software supports backing up to an external disk, another computer in your house and even a friend's computer (you can "barter" to back up each other's files). The backup files are encrypted, so nosey people can't poke around in your offsite backups.
I used the free version to back up my desktop, laptop and another laptop for about a year. I never once got hassled to sign up for the subscription plan. CrashPlan Free worked well and transparently. There were just several advantages to the subscription plan that I decided I really wanted. The first was having offsite backups to Code42's CrashPlan Central servers. The free version has daily scheduled backup (although I seem to recall being able to kick off an manual backup anytime I liked), whereas the subscription version has "continuous" backup. It's not absolutely keystroke-by-keystroke continuous, but it's within minutes of a file being changed. CrashPlan also has a mobile app that lets me access any file backed up to CrashPlan Central from anywhere. Both versions allow you to restore deleted files, but the subscription allows file versioning with - as far as I can tell - unlimited backup versions of a file. I am using the family plan which allows me to backup up to 10 computers with no data limits.
A couple of extra-cost services that I Code42 offers, which I have not used but am glad are available are the Seeded Backup service and the Restore-to-Door service. The Seeded Backup service exists to help get you going with offsite backup to CrashPlan Central. A drive is shipped to you and you backup to that drive. Then the drive is shipped to CrashPlan (shipping included in the cost) and they seed your cloud backup from there. I have a really good Internet connection, and it still took days to get my initial backups established on CrashPlan Central. If you have a slower Internet connection and lots of data to backup, this service is probably worth it.
The Restore-to-Door service is the opposite of the Seeded Backup service. If you had a catatrophic loss of data - say due to fire, flood or theft - that left you without a local copy of your data, you can have a disk with your last backup sent to you and you can restore it back to the same or another system. Once you are done restoring your files, you use the included return label to send it back.
I also find the CrashPlan support site to be be helpful and well done. There were some tips there that I had not even considered, one of which was the Gamer's Guide to CrashPlan. Since CrashPlan maintains multiple copies of changed files - including saved game files - I can always get back a previous game save (assuming I know where to find it) even if the game doesn't keep multiple saves. Most of the games I have nowadays were purchased from Steam. Getting the game files back is straightforward enough. However game saves is another matter. Some games synchronize the saves to the cloud (which has occasionally caused its own issues), but others don't. A way to be sure is to stick them on CrashPlan Central along with everything else.