Dropbox: You probably are familiar with Dropbox and we use their free account for some things only because we have some friends and relatives that require it. We will probably discontinue using Dropbox at some point as there are more secure and private options available now. We are not referring anyone to Dropbox as more secure options are available and we personally would not spend money on the service unless collaboration was a top priority.
P Cloud: Access from your Desktop without taking up space on your hard drive. It is a separate drive in the Cloud. Great deal on 2TB storage for life with no monthly or annual fees! More info >>> https://partner.pcloud.com/r/1983
Sync: This is a good option that we have used for several years. The service is good and reliable. It is private and secure. They have a great archive vault which relieves the space on your hard drive if you are using the optional Desktop App in addition to the Online account. More info >>> www.sync.goldenrulebenefits.com
I Drive: We have used IDrive for a few years now . They are an automated backup to the cloud company and they sent us a hard drive to copy our C:/ drive to and we returned it and they loaded over 600 GB to our 2TB account all online in our IDrive account in less than a week. More info >>> https://www.idrive.com/p=goldenrule