If your starting a blog or CMS there should be some plugins that in my opinion should be default.

Here is a list:

All in one SEO pack find it here http://wp.uberdose.com/

Google Site Maps Generator find it here http://www.arnebrachhold.de

A Contact plugin, There are a couple of good ones so you can check out the wordpress plugin database

Lighter Admin drop menus, this is for everyone not running WordPress 2.7