>>1553835 I suppose it depends on what you are going to store. With that in mind, do not store anything illegal in cloud storage. If you have a legal porn collection, just move it to an external HDD - those things are cheap and cheaper still with the after-Christmas sales if your country celebrates it. Finally, don't data hoard - it gets expensive and annoying trying to manage something that is of little practical use.
So you will want to use offline storage - well, you can't really go wrong with any of the services you mentioned. If you already have a Google account, you get 15GB with software that will sync with folders on your computer. MEGA does this as well and offers 20GB free with better options to share data with people who do not use MEGA.
OneDrive is a Microsoft service with 5GB free, but tied to Microsoft Office. Do you need Microsoft Office or use a Microsoft service?
