We don't really have a firm set of requirements here, and obviously that affects the advice.
I can assume that we want to protect against fire/flood, theft. For these you need offsite backups, or a good safe. Cloud offers automated backup while you're sleeping, but slow and not for free, on the upside, they handle all the messy RAID stuff for you. CD/DVD/BD sound great but are extremely time consuming and tedious, and you still have to be disciplined to physically take them someplace.
Local NAS. On local network, so GB backups are fast. You can run them on demand, and/or scheduled. AND you don't have to worry about paying for bandwidth used. Downside, not as turnkey as some would like. I have a netgear readynas ultra 2. Two disks, mirrored (RAID 1). Best for redundancy, not for performance. Like other NAS solutions, it supports lots of other features, has an ftp server, DLNA, etc.., etc...lots more. Not saying its the best one in the world, but it's what I went with. I use robocopy scripts to copy data to it.
Note, for scripts, onsite backups are fine, but it needs to be additive, NOT with a sync, else you run the risk of replicating the accidental deletion (d'oh!) or simply overwriting non corrupt data with corrupt data. If you are using robocopy, that means you want /e /s but NOT /mir.
How fast do you need to get the data back? An hour? Same day? A month?
For local workstation crash, accidental deletion. NAS gets the data back, fast and free, but of course there is upfront cost. Cloud gets the data back, ondemand, but SLOW, and might be subject to data consumption charges. CD/DVD/BD...gets the data back, but slow b/c you have to go get it. Tape I discount entirely. Too tedious, expensive and quite subject to obsolescence. If you'd archived with top of the line SCSI tape system 10 yrs ago, you'd be kicking yourself today trying to use it to restore data.
I don't have a solution for this one either...yrs ago a few of us talked bout hosting ftp sites for one another at each other's houses, but that is hardly permanent/reliable either, plus the bandwidth hogging issue. I am thinking about 7zip ing all of it (with verify switch) and dumping it to USB3 removable storage and putting it in a safe at home every so often. Of course, neither USB nor sata is future proof, but its the closest thing we have right now, and it's cheap/scriptable.
One note about defragging...it's on by default in Win7, and presumably, Win8. Not sure diskkeeper is adding any value. In Windows server, you can schedule it with defrag.exe.