Not going to go into why you should backup, but here is how I handle the things that matter to me: Code, Documents, PC Games, and Photo and Video.
Documents and other miscellaneous files
Some prefer Microsoft, Google, or another company. Take your pick (numbers from time of writing):
Just use Steam.
Photo and Video
- Unlimited uploads and storage
- Unlimited sets and collections
- Access to your original files
- Stats on your account
- Ad-free browsing and sharing
- HD video uploads & playback
Their upload download procedures aren't super smooth, but I mostly do uploads and the Flickr Uploadr makes that pretty easy. I tried out Google's Picasa a while back, but with my massive collection of family photos it was getting very expensive very fast.
I also have a Synology DS211J NAS that I use to store all my photos and videos in house. If you edit/view/print your photos a lot, having this local network copy/cache will help out a lot.
Bonus: I have 2 projects on Github relating to photo management.
"Organize My Photos" aims to organize all of your local photos into folders by date. It's a really basic/ugly implementation in Winforms, but it works for my purposes.
"Organize My Flickr Photos" aims to keep your photos "backed up" to Flickr, avoiding duplication. I don't think this code is fully functional right now. Last I checked I was fighting with the limitations of the Flickr API. Once over those hurdles it shouldn't be too much work to get some nice sync action going on.