I use a Network Attached Storage unit with RAID-enabled Terabyte drives. If a drive fails, no worries; the other drive still carries the data, and you can swap out the bad drive and it will replicate once that's done.
BUT, the safest AND best way is to have two backups of your data. So, have a copy off of your computer, AND an off-site location if it's data that you cannot afford to lose.
The problem with carbonite is that it's a recurring charge. For many of us, it's an extra bill we don't want.
Personally, I have lots of data I don't want to lose, but wouldn't make me lose my job or some other major aspect of my life if it got destroyed, so I just keep my RAID-enabled NAS and leave it at that.