STATS FOR THE BLOG OWNER
AWStats Xtended Info - Requires AWStats and adds things such as screen size, Flash, PDF, and Java support.
Backlinks inbound links counter - Uses MSN to track all your incoming links to your site, not just from blogs.
Bluetrait Event Viewer (BTEV) - Good stats package for security as it tracks your logins, deleted users, last passwords, invalid user names and more. Good way to keep an eye on what's happening in a multi-user blog.
Bsuite - Tracks page loads, search terms used on incoming links, shows top performing posts, lists related posts at the bottom of each entry and more.
CountPosts - Shows you how many times each post gets visited, ignores visits from you as long as you are logged in as admin.
DownloadCounter - WordPress allows you to attach downloads to posts, but gives you no way to count the downloads. This plugin will let you know in your admin panel.
Dschini Bot Checker - Lets you know which pages are being checked by which search bots and how often.
Feed Statistics - Monitors your feeds and tells you which readers are being used, the links the readers click on, and which stories they are reading.
FeedBurner SiteStats Enabler - Helps you install the FeedBurner script in your site, instructions in both Italian and English.
FeedBurner StandardStats - Helps simplify the process of installing the FeedBurner script so you can monitor your RSS feed statistics.
FeedStats - Statistical tool for counting your feeds, measuring length of stay on your site and more. Stats appear in the dashboard.
FirStats - Full-featured, Ajax powered stats for your admin area, smooth movement between pages with no need to reload whole page.
GoStats web counter - Lets you install the GoStats counter in your blog, easily installed in a text widget.
Lightstats - Plugin generates bar and pie graphs for statistics about posts, comments, and categories.
Live - Lets you watch the activity on your blog in real time. See things like posts visited, comments left and feeds grabbed.
Open Web Analytics - Track page views, visits, unique visitors, clicks, referring websites, plot visitor geography on Google Earth, and much more.
Posts/Comments Time - Ever wondered when you should aim to make your posts? This plugin shows you the number of posts and comments for the hours of each day so you can better plan your posting times to be before your high comment periods.
Search Phrases - Straightforward plugin that just displays what search terms brought the visitors to your site.
Social Traffic Monitor - Monitors the social sites Digg, Netscape, Reddit, Newsvine, Fark, Slashdot, Del.icio.us, and StumbleUpon, when someone comes from one of those, it begins keeping records and displays the data to you in a bar graph.
Ultimate Google Analytics - Adds the Google Analytics script to your site as well as counts downloads and outbound links for you.
Word Count - Sometimes you need to know the number of words in your post for blogging challenges, setting goals for yourself and more; this plugin will do it for you.
WordPress.com Stats - Uses your WordPress API key to pull stats and puts them all in a centralized page in your admin area.
WP OnlineCounter - This plugin counts the number of currently online, highest number of visitors at the same time, and the total count of visitors. Can also configure what is displayed to the visitors.
WP-SlimStat - Tracks all of the standard stats you've come to expect from a stats package, but in a very compressed database for less load on your server.
WP-Stats - Very general statistics package focusing on your number of posts, comments and so on.
STATS TO SHARE WITH VISITORS
Akismet Spam Count - Show off your Akismet spam power and let spammers know you're protected from their attempts.
Alexa Rank - Allows you to display your Alexa rank for the world to see.
GeneralStats - Displays your choice of number of users, categories, posts, comments, pages, links, words in posts, words in comments and words in pages.
Google PageRank - Display your Google page rank on your front page, useful when trying to attract some advertisers.
Impress - Display number of users, posts, pages, comments, categories, words, and more on your blog for visitors to see. (via)