Google Drive gives you 15 GB free with options to expand! The unique thing about this option is that you get free storage for all items created from inside Drive (docs, spreadsheets, and presentations). Oh, and you use your existing Google Account. Nice!
Important photos stored for free? Done. ---> Google Photos Uploader
If you have a server to backup -- especially one with a ton of storage -- this is your huckleberry. Unlimited storage for your device(s) at a price point worth paying for!