Best WordPress plugins for security, backup and spam protection in your WordPress based site.
Best Spam Blocker Plugin: Akismet
It checks your comments against the Akismet web service to see if they look like spam or not.
Best WordPress Backup Plugin: BackWPup
Backups your WordPress site and do more like Keep File Backup, Keep Database Backup, Store backup to Folder, Easily Optimize Database, Send Log/Backup by Email, Do WordPress XML Export, Store backup to FTP Server, Store backup to Amazon S3, Easily CheckRepair Database, Multisite Support only as Network Admin, Store Backups in zip, tar, tar.gz, tar.bz2 format, Store backup to Google Storage, RackSpaceCloud, Microsoft Azure (Blob), Dropbox, SugarSync
Best User Activity Logging Plugin: WP-Activity
It logs activity of all registered users in your blog and displays it in frontend and backend. This plugin can also track and deny access by blacklisting to unwanted login attempts. Activity logged includes logon, new user, new comment, comment edition, comment deletion, profile update, new published post, published post edition, post deleted (really deleted, not trashed), new link, login failure (displayed only in admin panel), access denied by IP blacklisting (displayed only in admin panel)
Best WordPress Security Scanner Plugin: WP Security Scan
Scans your WordPress site for security vulnerabilities then it suggests corrective actions like Passwords, File permissions, Database security, Version hiding, WordPress admin protection/security, Removes WP Generator META tag from core code
Best WordPress Security Feature Plugin: Better WP Security
Popular easiest, most effective way for securing WordPress and improving security in seconds.
Best Plugin for Limiting Login Attempts: Limit Login Attempts
Easily limit WordPress login attempts, including by way of cookies, for each IP. Fully customizable.
Best Way To Force Strong User Passwords: Force Strong Passwords
Forces users in your WordPress site with executive capabilities to use something strong while updating their passwords.