For DIY offsite backup I use crashplan. Their system lets you use their servers if you choose (for payment) but it also lets you use a remote disk you have over at a freinds house too, or one attached to your computer. I bought their software after using the free version for years. Besides being a nice automated backup system, the killer thing was the ability to backup offsite to a friends house. I do it mutually with them, each keeping the other's USB disk at our respective homes.
What's great about this is that if I do ever need to do a full backup, I don't have to try streaming it back through a soda straw over the web. I just drive the station wagon over, pick up the disk, and bring it home. Station wagons have very high bandwidth.
The disk is encrypted so no worries about peepers or what happens if my freinds computer gets broken into.
The payware version is a one time payment not a monthly fee. What you get for the payware version is more parsimonious differential backups and some other features about controlling backup times.
The software has gotten much better over the years too. Early on my complaint was the java bloated itself out to huge memory sizes over time. But now I don't even notice it is running.
Anytime I need to do a bigger than normal backup, I go get the disk and attach it locally, then take it back. That only happens when there's an unusual event. For example, if I make a major change in the structure of my file system, copy everything to a new disk or do something that touches all the files, then this could, in most backup systems, trigger a level 0 backup. So when that happens it's much easier to get things up to date then with any on-the-net storage system.