I still need to add a few more but so far I’ve added the following 10 WordPress plugins:

1. Akismet - a great comment spam plugin. Interestingly I had comment spam on TwiTip that Akismet filtered within minutes of launching the blog on Twitter.
2. All in One SEO Pack - a plugin that helps to optimize a blog for search engines. It gives easy ways to set up title tags, descriptions, keywords (both for home pages but also on individual posts) and a variety of other settings that have an impact upon SEO.
3. cforms - a powerful contact form plugin. It’s a lot more complex than other comment form plugins out there but has a lot more features (some that I’m yet to fully test).
4. Google XML Sitemaps - a plugin to help Google and other search engines to find every page and post on your blog - good for getting a new blog indexed quickly.
5. Simple Tags - extends the built in tags features on WordPress.
6. Subscribe To Comments - a WordPress plugin that allows those leaving comments to check a box and be notified when other people leave a comment on that thread.
7. Tweet This - ads an invitation for readers to Tweet a link to the post they are reading. While I wouldn’t put this on every blog - it seemed a no brainer on a blog about Twitter.
8. WordPress.com Stats - I’m using Google Analytics as my main metrics tool for TwiTip but it doesn’t update in real time so this plugin helps to get a quick update of what’s happening on the blog at any given point in time.
9. WP-Polls - an AJAX polling plugin with some nice features. I’ve previously used the Democracy Plugin but this one seems to be working really nicely so far.
10. WP Ajax Edit Comments - this plugin allows those leaving comments to edit their comments for a short period of time after they leave a comment.

These are just the first 10 that I’ve already installed (listed in alphabetical order and not in order of importance). There are more to come. For example I’ll install Related Posts (pointless at this point as there are only 5 posts on the blog), WP-Navi (again, no point to install it yet as I don’t have enough posts to need a navigation tool) and WP Super Cache (I’m not doing enough traffic to really need it yet).