Wordpress is my CMS and blog platform of choice.  I have tried a lot of different programs in the past, Geeklog, Drupal, Joomala, and even PHP-Nuke.  However the power and simplicity of Wordpress has made it the one for me.

Here is a list of the plugins that I install on EVERY site that I start either for myself or for a friend.

1. Add-Sig – This addon is great for adding a signature to every post.  I put in my twitter link, a reminder to add my feed at the bottom of every post.  Remember to keep it short though, you don’t want your signature to over-whelm your visitors.
2. All in One SEO Pack – If you are going to do nothing else for SEO, install this plugin and use it.  This plugin allows you to give every post its own title and meta information.
3. Google Analytics for Wordpress – This is the easiest way to add your site to Google Analytics without having to modify your theme.  This plugin also gives you the ability to NOT track the information of the admin which will give you a better idea of the traffic on your site when you are starting out.
4. Google Sitemap Generator – Google loves its sitemaps.  I know I said above that if you did nothing else for SEO you should use the All in One SEO Pack, well you should install this too.  With this you just have it install it, and every time you make a post it will add it to a XML sitemap that Google will use to hopefully index your site.
5. Contact Form – One of the things that Wordpress doesn’t have built in is a good contact form.  This plugin will allow you to add a contact form and allow your readers to get in contact with you, without you having to worry about making email public….if you’re worried about that sort of thing.
6. Twitter Widget – You’re on Twitter….right?  Well if you are and you have a Wordpress blog you know that the widgets that they have suck.  This plugin gives you a widget that will match your theme and allow your readers to see what you have been talking about on Twitter.
7. What would Seth Godin Do? – Seth Godin once said in his blog that you should use cookies to ensure that visitors to your site get a unique experience.  This plugin allows you to give first-time visitors to your site a special message.  With this message you can welcome them, point them to other great posts, and tell them where to go next.
8. Wordpress Super Cache – So you just started a blog and you are wondering why you need a caching system.  Well be positive, your blog will be popular enough and if you get a huge traffic spike you want to be sure that your site can handle it.  So install it, test it, and be ready for everything.
9. Yet Another Related Posts Plugin  – This plugin puts a list of past posts that you have made with the same tags as the one that your visitor is reading.  This gives the blog more stickiness so that your visitor has somewhere else to go when they finish reading the post that got them there.

These are my must have plugins for every wordpress installation.  What are some plugins that you would recommend for all wordpress users, or how about alternatives to the ones that I have listed here.