I care a lot about my data (and so should you). Because of this I keep all of my code and all my documents under version control using git. Media files are not modified very often which makes version control less important.
Still losing all your music or your video collection is a horrible experience but here comes git-annex to the rescue. It allows you to manage your files from a single location, you can add new files, remove files, rename or move files and then propagate these changes to multiple disks or servers.
Many people don’t do backups at all. Some do but not regularly. Some do them regularly but they never try to restore their data. Just assuming that your backup system works in the reverse direction is naive and dangerous, but it’s all too common. If you use a distributed version control system the problem goes away. Every client then has a full backup of all your data. In the case of git-annex this is not necessarily the case but it allows you to configure a policy that forces you to store file X in at least Y different repositories.
Finally I use Time Machine too as it allows me to very quickly get back on track if I need to reinstall my complete system. For the moment Time Machine is also responsible for my photos and my music. If you don’t use a Mac then checkout rsnapshot or DeltaCopy. If you find these systems hard to use you can store your data in the cloud using Dropbox (2 GB free) or Box.net. Use the right tool for the right job!
If you lose all your family photos there is no one else who can help you get those memories back. Start doing backups!