This outlines a standard list of WordPress Plugins you can start with for any common deployment. This list can act as a basic boilerplate leaving the user to pick and choose due to need.
Google XML Sitemaps
This plugin will generate a special XML sitemap which will help search engines like Google, Bing, Yahoo and Ask.com to better index your blog. With such a sitemap, it’s much easier for the crawlers to see the complete structure of your site and retrieve it more efficiently. The plugin supports all kinds of WordPress generated pages as well as custom URLs. Additionally it notifies all major search engines every time you create a post about the new content.
Contact Form 7
Contact Form 7 can manage multiple contact forms, plus you can customize the form and the mail contents flexibly with simple markup. The form supports Ajax-powered submitting, CAPTCHA, Akismet spam filtering and so on.
W3 Total Cache
Improve site performance and user experience via caching: browser, page, object, database, minify and content delivery network support.
Widget Logic
This plugin gives every widget an extra control field called “Widget logic” that lets you control the pages that the widget will appear on.
Query Postss
The Query Posts widget was written to allow users that don’t know their way around PHP to easily show posts in any way they’d like. It’s like having a cool WordPress developer as a friend ready to do your bidding. Seriously.
Custom Post Type UI
This plugin provides an easy to use interface to create and administer custom post types and taxonomies in WordPress. This plugin is created for WordPress 3.x.
Get Custom Field Values
Use widgets, shortcodes, and/or template tags to easily retrieve and display custom field values for posts or pages.
Administrative Tools & Customization
WordPress File Monitor
Monitors your WordPress installation for added/deleted/changed files. When a change is detected an email alert can be sent to a specified address.
Robots Meta
This plugin makes it easy to add the appropriate meta robots tags to your pages, disable unused archives, nofollow unnecessary links as well.
Login Logo
This plugin allows you to customize the logo on the WordPress login screen. There is zero configuration. You just drop the logo file into your WordPress content directory, named login-logo.png and this plugin takes over.
White Label CMS
The White Label CMS plugin is for developers who want to give their clients a more personalised and less confusing CMS. You have the ability to choose which menus appear. We have 3 CMS profiles of Website, Blog or Custom so you can modify the menu system to suit the CMS purpose. These only apply to user role of Editor and below.
WP-DB-Backup
WP-DB-Backup allows you easily to backup your core WordPress database tables. You may also backup other tables in the same database.
Author Note: I generally handle my database backups using other methods, but I had to use this plugin for a very specific task and it performed admirably.
Social Media Tools
Facebook Comments
Facebook comments can be annoying to set up. This plugin makes it simple to add the Facebook comments system to your WordPress site without much hassle.
Topsy Retweet Button
Provides a Twitter retweet button for your posts that shows all tweets, enables retweeting, and adds tweets as comments.
Fanpage Connect
Fanpage Connect is the WordPress plugin that allows you to create an administer your Facebook fan pages directly from WordPress.
Social Profiles Widget
This plugin/widget allows you to insert icon links to your social profiles in any widgetized area.
WordPress Development
Simple Show IDs
Simply shows the ID of Posts, Pages, Media, Links, Categories, Tags and Users in the admin tables for easy access. Very lightweight.
Velvet Blues Update URLs
If you move your WordPress website to a new domain name, you will find that internal links to pages and references to images are not updated. Instead, these links and references will point to your old domain name. This plugin fixes that problem. This Update URLs plugin updates all urls and content links in your website.
WP Maintenance Mode
Adds a maintenance-page to your blog that lets visitors know your blog is down for maintenancetime. User with rights for theme-options get full access to the blog including the frontend. Activate the plugin and your blog is in maintenance-mode, works and see the frontend, only registered users with enough rights. You can use a date with a countdown for informations the visitors or set a value and unit for infomrations. Also you can add urls for exlude of maintenance mode.