Back-end:

Ozh’ Admin Drop Down Menu - CSS dropdown menu bar, fast access to control panel options.

TinyMCE Advanced - adds missing functionality to your editor (e.g. font handling, html table support).

My Link Order,  My-Page-Order and My Category Order – set the appearance order of pages, links and categories through a drag and drop interface (note that My-Link-Order and My-Category-Order use their own widgets!)

Exclude pages Add a check box to exclude page from appearing in menu, useful if you don’t want all the pages on your main menu.

Exec-PHP Enables the execution of PHP commands on your pages or sidebar.

SEO:

All in One SEO Pack – Provides everything you need to optimize your website.

Google XML Sitemaps – Automatically generates and updates your site’s XML sitemap, automatically notify major search engines about updates.

Statistics:

Google Analytics for WordPress – Enable Google’s Analytics. Need a Google Analytics’ UID. I tried WordPress.com Stats but had issues with my other sites login, e.g. my wordpress.com blog that is always in login, I had to change my login to view the stats. StatPress is also includes but deactivated, I was looking for stats that will work out of the box, Google Analytics and WordPress.com stats plugins need to be configured after activation, this one works immediatly after activation. it stores statistics in the sites database and that could be considered a minus. Google Analitycs can send scheduled email reports and that another advantage

Spam Protection:

WP-SpamFree – I’m test riding this one, Akismet works great and much more popular but needs a WordPress.com API key (and I really want stuff to work out of the box). Note that if you build a small business or corporate website you probably don’t want people to comments or your pages or newsletter, in that case comments will be blocked and there will be no need for comment spam protection.

Database Backups:

I’m was looking for a simple and light backup plugin, so that I can click a button instead of going to  PhpMyAdmin  to do manual backups. WordPress Database Backup do just that, plus it also support schedules backups, Restore (if needed) is done with PhpMyAdmin. I had the more popular and complex database manager/backups installed in the past, but had some issues.

Forms:

Contact-Form-7 easily define forms and other forms and gather information from visitors.

Newsletter:

Subscribe2 Subscribe to post notification by email, can be used for newsletters, content and appearnce of emails can be costomized.

Image and gallery management:

NextGen Gallery plugin has the best ever management facility, and some cool flash addons ( NextGEN-FlashViewer, NextGEN-ImageFlow, NextGEN Smooth Gallery). I used the FalshViewer, it looks great but doesn’t link from the page to the images, so you need to do something else for the images SEO, ImageFlow does link to the pics.

You can easly convert your NextGen gallery to a shop, using WordPress Simple Paypal Shopping Cart plugin. I tried it here and it works nicely. WordPress eStore Plugin is similar to the simple paypal shopping cart plugin with the added capability to sell digital products, this one cost 10$ or so.

Shockingly Simple Favicon set your favicon through the admin panel.

Not includes by default by highly recommended:

Multi-language support:

Tried 4 different multi-language support plugins, qTranslate was the best, I personally prefer to have a separate WordPress installation in a sub directory for each language, so this plugin is not included in the pack.

Loading speed:

wp-super-cache will generate static HTML cache for pages, if you have a powerfull server you will not really need it but if you are on shared hosting on a busy day… this thing might have some side effects.

WEBO site speedup – This thing reduce the number of object sent to the browser on a page request, plus those a lot of  other things to speed up you site, has a free and a  paid version.