This is a working list of plugins that I use regularly on WordPress websites
Contact Form 7 – Just another contact form plugin. Simple but flexible.
Maintenance Mode – Adds a responsive maintenance mode page to your site that lets visitors know your site is down.
UpdraftPlus – Backup and restore: take backups locally, or backup to Amazon S3, Dropbox, Google Drive, Rackspace, (S)FTP, WebDAV & email, on automatic schedules.
White Label CMS – A plugin that allows you to brand WordPress CMS as your own
Yoast SEO – The first true all-in-one SEO solution for WordPress, including on-page content analysis, XML sitemaps and much more.
Shortcodes Ultimate – Supercharge your WordPress theme with mega pack of shortcodes
Social Media Auto Publish – Publish posts automatically from your blog to social media networks like Facebook, Twitter and LinkedIn. The plugin supports filtering posts by post-types and categories.
UberMenu 3 – Easily create beautiful, flexible, responsive mega menus
jQuery Colorbox – Used to overlay images on the current page. Images in one post are grouped automatically.
Responsive Gallery Grid – Converts the default wordpress gallery to a Google+ styled image gallery grid, where the images are scaled to fill the gallery container, while maintaining image aspect ratio’s.
WooCommerce – An e-commerce toolkit that helps you sell anything. Beautifully.