1. Akismet- It is hard to grow a site when you keep getting comment spam. Hardly anything gets through, and it is very simple to use.
2. All in One SEO Pack- This optimizes like you wouldn’t believe. You can fix your titles, keywords, descriptions, block spiders, and more. I’ve been able to get great results with small sites.
3. FeedBurner FeedSmith- You can manage your feed subscribers much more easily and utilize the great functions of FeedBurner.
4. Google XML Sitemaps- A great boost to SEO. Google uses sitemaps to help them determine what information should be indexed. This plugin helps.
5. Lighter Menus- Let’s face it, drop down menus are much faster to navigate, and you don’t need to waste time or space when working on your site.
6. Plugin Central- Easily install and update plugins from your dashboard. Since you don’t need to use ftp anymore, you can quickly manage plugins anywhere.
7. Subscribe To Comments- Let people receive notification that someone responded to their comment. It may be useful to them, and may also bring them back to the site. Always encourage discussion.
8. WassUp- Real time stats (OS, browser, host, referrer, location, top content, top searches) help you determine which content and marketing efforts are working, and give you immediate satisfaction when you have site visitors. Plus, there are great sort options.
9. Wordpress Thread Comment- The site may be hard to understand, but setup is simple, and you get an attractive, useful implementation of threaded comments upon activation.
10. WP-DBManager- You never know if something will go wrong with your database. Back it up and optimize it at least once a month.

Notable omissions:

• WP Super Cache- When your site becomes a hit, you will probably want to cache your pages so your server is not overrun. For sites with less traffic, a cache plugin can be annoying since you can not see updates to your site immediately.
• Post-Plugin Library- Great for a power user, it lets you use the connected Similar Posts, Recent Comments, and Random Comments. I was able to combine with the custom field to display an image with each similar post. However, it breaks many other plugins and can cause errors in WordPress.

What other plugins do you use?