Insync is, by far, the best of the best for syncing Google Drive to your desktop. Not only can you sync multiple Google accounts, but you can determine what is synced, where it is to be synced, as well as work with teams, get notifications on your desktop, preserve directory structure, merge folders, share files/folders from the desktop, and so much more.
Dropbox is one of the cloud sync leaders on the market. And with a desktop app that’s hard to beat, Dropbox absolutely belongs on this list. With the Dropbox desktop app, you can view notifications, get share links for files, open either your local or remote Dropbox folders, open files, pause syncing, snooze notifications, and gain access to Dropbox preferences. The Dropbox desktop client integrates seamlessly with your file manager and lives in your desktop system (or notification) tray. Dropbox doesn’t offer too much in the way of bells and whistles, but if you’re a user of this particular cloud service, you cannot beat the reliability and ease of use found in their client app.
Duplicati is a bit different than most desktop sync apps. Instead of being a standard desktop client, it acts more like a web-based app (running on its own, built-in web server), and allows you to sync/back up to a multitude of hosts (such as SSH, SFTP, WebDAV, Azure, B2, Box, Dropbox, Google Cloud, Google Drive, OneDrive, and many more). How you set up a sync connection depends upon the service you use, but most configurations aren’t terribly challenging.
GoodSync is an incredibly powerful desktop syncing app that can work as either a backup or a sync tool. In fact, GoodSync is so powerful, it can pretty much fill any desktop sync/backup need you have. GoodSync features real-time data transfer, block level transfer, unattended service, end-to-end encryption, version control, copy-locked files, file/folder move/rename detection, security attribute propagation, bandwidth throttling, and more.
Odrive is a powerful sync client that supports many popular cloud services (such as Google Drive and Dropbox) as well as file sharing protocols like FTP and SFTP. The Odrive client exists as a system tray pop-up menu and offers plenty of options from that easy-to-access window. Odrive features end-to-end encryption, network drive support, unlimited cloud connections, odrive folder relocation, auto download, bandwidth throttling, large file splitting, auto empty trash and many more.