Which backup program is best? An unbiased opinion, please.

i think NovaBackup is the best, it costs $45 , but it is highly rated

I tried Acronis, Shadowprotect and Paragon backup applications.

They works fine initially. But when running them continuously, the storage usage goes high and find it difficult.

How is your backup plan? Are you going to backup at your local backup location or backup to remote location or cloud?

Have you tried Vembu StoreGrid?

Using StoreGrid, you can backup to local disk (completely free with out any limitation). It supports image backup and major applications backup. It supports incremental backup with automatic cleanup of old data. It also supports setting up backups to remote backup server, cloud and local backup server.

Just download your copy and try it your self.
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Aravind