Thanks to the large WordPress community there are a lot of WordPress plugins available. The downside though is that you normally have to try out a few different plugins before you find the one that meets your needs.
To save others the same pain I’ve collated the following list of plugins that I use frequently across a number of websites.
All in One SEO Pack
Extensive options for adding SEO to your website. Optimisations can be made globally and on a post/page level.
Allow PHP in Posts and Pages
Create PHP code snippets that can then be called in posts using shortcodes.
Black Studio TinyMCE Widget
Adds a WYSIWYG text widget.
Breadcrumb NavXT
Flexible plugin allowing you to add breadcrumb trails to your website that also supports custom post types.
Broken Link Checker
Checks content for broken links.
Capability Manager Enhanced
Manage WordPress roles and capabilities allowing the creation of new roles with custom capabilities.
CMS Tree Page View
CMS style tree-view that allows you to organise the hierarchy of pages effortlessly.
Contact Form 7
Add forms to pages and posts easily!
Contact Form to DB Extension
An extension for Contact Form 7 that saves form data in a database table. There is also an interface to query and edit the data captured.
Custom Post Type UI
Allows you to set up custom post types through and interface rather than programatically.
Disable Comments
Disable comments for a post type.
Disable Parent Menu Link
Disable hyperlink for parent pages when children are listed in navigation menu.
Events Manager Extended
Advanced events management with support for locations and recurring events.
File Un-Attach
Attach and detach files to/from posts.
Flickr API
Easy to use (and extend) Flickr API for displaying your photostream and flickr sets.
Google Analytics
Adds Google Analytics and gives you an option to use the asynchronous tracking code.
Google XML Sitemaps
Creates an XML sitemap of your website content. Extensive options allow you to restrict what is included in the generated sitemap.
GUAR Google XML Sitemaps
Enhances Google Sitemaps plugin to support custom post types.
Hide Login Logo
Hide the WordPress logo on the login page.
Hierarchical Pages
Display list of pages in widgets using advance options to control depth, excluded content, siblings and more.
Hierarchical Pages
Collapsing hierarchical pages widget with options to enable children.
Insert Headers and Footers
Easily add scripts to the head section or before the closing body tag - great for adding tracking code without editing template files.
Links Shortcode
List links in posts using a shortcode. Custom HTML formatting is supported. 'Links Shortcode' was used to list all of these plugin links!
List Pages Shortcode
Use shortcodes to add lists of pages, for example child, related and sibling pages.
MCE Table Buttons
Adds a HTML table editor button to the TinyMCE WordPress visual editor. The number of columns and rows can easily be specified.
Memory Usage Bar
Display current memory usage in the admin header.
Multiple Post Thumbnails
Allows multiple featured images to be assigned to one post.
My Page Order
Easy page ordering with a drag and drop interface.
Next Page, Not Next Post
Add next/previous links for pages (like posts have) via shortcodes.
No Comments On Pages
Disable comments for all pages at once.
p2pConverter
Easily convert a post to a page or a page to a post.
Permalink Fix & Disable Canonical Redirects Pack
Makes WordPress' permalinks functionality work properly when running WordPress on Windows - note this plugin has only been used in a development environment.
PHP Code Widget
A text widget that allows will process any PHP code entered.
Post Types Order
Specify the display order of posts, pages and custom post types.
Private WordPress
Simple plugin to make your WordPress website completely private.
Raw HTML Snippets
Create HTML snippets (HTML, CSS & JavaScript) that can then be embedded in pages/posts without WordPress tidying the HTML.
Redirects
Easily create 301 redirects to map old URLs to new ones - also has a CSV file import option.
Regenerate Thumbnails
Automatically resizes all of your images using the current Media or custom image settings.
Simple Custom CSS
Add custom css that is independent of the theme.
TinyMCE Spellcheck
Adds spellcheck functionality for the TinyMCE editor.
TOC For WordPress
Use shortcodes to create a table of contents in your post or page that is generated from the HTML headings of the content.
Tweet & Like
Displays Twitter and Facebook social buttons optionally on all posts or as a widget. Has an AddThis option too.
Wickett Twitter Widget
Display latest tweets from a Twitter account in a text widget.
Widget Settings Importer/Exporter
Import and export widget settings from one website to another. This is very useful when moving websites between development and production environments.
WordPress Access Control
Restrict access to WordPress content based on user roles.
WordPress Backup
Backup up your WordPress files with options to schedule and email the compressed files.
WordPress Importer
Import content from WordPress XML export file.
WP Htaccess Editor
Edit the .htaccess file through the WordPress admin.
WP Robots Txt
Edit the robots.txt through the WordPress reading settings page.
WP-DB-Backup
Backup WordPress core database and other tables in database. Backups can be automated and emailed.
WP-PageNavi
Adds numerical pagination instead or normal older and newer links
WP-Polls
Create simple polls to add to your website.
ZigTrap
Automatically adds a honey pot to comments forms to help block spammers.