BackBlaze doesn't have an offline component, so you'll have to handle that yourself, but it's by far one of the most affordable options on the market. Accounts are $5/mo (you get a break if you pay up front for one or two years), and you can add more computers to the same account for another $5/mo. You can read more about Backblaze's pricing options here.

Bitcasa starts you off with 10GB for free, but $100/yr throws the floodgates open and gets you unlimited storage for anything you want to sync, share, or back up. Plus, you can connect as many computers or devices to your account as you choose, so you don't pay by the PC. It's client isn't quite as robust as some of the other tools here, but if you're more interested in a flat fee for unlimited space and you can handle the details of which files go where and when, it's a solid option. You can read more about Bitcasa's pricing here.
Most services encrypt your files with strong systems such as AES 256 before sending them up to the servers over an encrypted connection. The majority of products we tested also offer a private encryption key option. If you choose to manage your own encryption keys (basically the "key" that decrypts your backup), know that it is your responsibility to remember it. The online backup service itself will not be able to help you reset the password if you forget it. On the flip side, this means that no one (including employees of the backup service and law enforcement officials) other than you can unlock your backups. This is ideal from a privacy and security standpoint. Use a password manager to keep track of your private encryption key if you think you will forget it.
Another problem many people run into with not downloading videos is that they often forget how they got there in the first place. You might forget the title or who posted the video or even some of the key features. That makes it difficult to find the video again in the future. When it comes to downloading those videos, however, you won’t have to worry about that because you’ll have the videos you like to watch available right there. You won’t have to worry about how you’re going to track it down later on because you’ll have it in whatever folder you want with a name that means something to you.
There are a few common practices for configuring when backups occur. The most common option is on a fixed schedule, such as once a day, week, or month. The second, which we prefer, is to upload file changes whenever they're changed and saved, otherwise known as a continuous backup setting. Services only transfer the modified part of the file in this scenario, so as not to overburden your internet connection or take up unnecessary storage. A third way is simply to upload files manually. Some may appreciate this degree of control, but this method is only effective if you remember to regularly run the backup.
CrashPlan is completely free if you're just doing local backups, but even online backups are affordable, with CrashPlan+ accounts starting at $2/mo (per computer) for 10GB of online backup storage, and going up to $4/mo (per computer) for unlimited online backup storage and $9/mo for unlimited online backup storage for a whole household. You can check out their plans here, and try them free for 30 days with a new account.