Being a WordPress enthusiast I am always getting asked what are the the best plugins for various outcomes. Below is an inventory of the plugins I  enjoy using. Some have help me  by getting quality search traffic, increasing social signals , increasing revenue, decreasing load time, implementing  nofollow links and much more.

Adding Ads Within Content

• Ad Injection – Injects any advert (e.g. AdSense) into your WordPress posts or widget area. Restrict who sees the ads by post length, age, referrer or IP. Cache compatible.

Authors Images

• Metronet Profile Picture – Use the native WP uploader on user profiles page to upload a specific image. Excellent for those who have contributors.

Contact Forms

• Contact Form 7
• Fast Secure Contact Form
• Grunion Contact Form – Add a contact form to any post, page or text widget. Emails will be sent to the post’s author by default, or any email address you choose

Creating Tables

• Websimon Tables – Create and style tables for wordpress posts and pages

Decrease Bounce Rate

• Related Posts Thumbnails – Showing related posts thumbnails under the post.
• Simply Related Posts – A widget that simply gives you related posts by taxonomy.
• WordPress Popular Posts – Showcases your most popular posts to your visitors on your blog’s sidebar. Use WordPress Popular Posts as a widget or place it anywhere on your theme using <?php wpp_get_mostpopular(); ?>

Decreasing Site Load Time

• W3 Total Cache – The highest rated and most complete WordPress performance plugin. Dramatically improve the speed and user experience of your site. Add browser, page, object and database caching as well as minify and content delivery network (CDN) to WordPress.

Ecommerce

• WP Simple Paypal Shopping Cart – Simple WordPress Shopping Cart Plugin, very easy to use and great for selling products and services from your blog
• WooCommerce – An e-commerce toolkit that helps you sell anything

Genesis (StudioPress) Specific 

• Genesis Simple Edits – Genesis Simple Edits lets you edit the three most commonly modified areas in any Genesis theme: the post-info, the post-meta, and the footer area.
• Simple Social Icons – A simple, CSS and sprite driven social icons widget.
• Genesis Simple Hooks – Genesis Simple Hooks allows you easy access to the 50+ Action Hooks in the Genesis Theme.
• Genesis Connect for WooCommerce – Allows you to seamlessly integrate WooCommerce with the Genesis Framework and Genesis child themes.

NoFollow 

• Outbound Link Manager – The Outbound Link Manager monitors outbound links in your posts and pages, easily allowing you to add or remove a nofollow tag, update anchor texts, or remove links altogether.

Redirect/Broken Links /404

• 404 Redirection – Permanently redirect all 404’s to the main blog URL. The primary purpose is to salvage Google PageRank (TM) from missing pages.

Richsnippets 

• All In One Schema.org Rich Snippets – The All in One Rich Snippets gives the power to the blog author to control the rich snippets to be shown in the search results by the search engines.

SEO – General

• WordPress SEO (by Joost some know it as Yoast) – The first true all-in-one SEO solution for WordPress, including on-page content analysis, XML sitemaps and much more.
• SEO Data Transporter – Helps you transfer post/page specific SEO data, like custom doctitles, custom META descriptions and keywords, etc., from one platform (theme or plugin) to another. Note-When everything is updated, deactivate the plugin, or it will overwrite and not let you update the META decriptions in WordPress SEO by Yoast.

SEO – Drives Quality Traffic to the Site

• Tweetily – Tweetily will periodically tweet a random post or page automatically to promote your content and drive traffic to your Web site! You set the time, number of tweets, and just let Tweetily do the rest!
• Twitter Publisher – Share a new blog post on Twitter using awe.sm shorten url service. Support for main blog account and per author twitter accounts. Main Twitter account can reference author’s twitter/display name in the tweet.

Social Media

• Flare – Flare is a simple yet eye-catching social sharing bar that gets you followed and lets your content get shared via posts, pages, and media types.
• Simple Social Icons – A simple, CSS and sprite driven social icons widget.

Other

• Reveal IDs – Reveals hidden IDs in Admin interface that have been removed with WordPress 2.5 (formerly known as Entry IDs in Manage Posts/Pages View for WP 2.5).
• Plugin Activation Date – Shows when each plugin’s status was changed. Useful in instances where many plugins are installed.