I have been looking for a great web analytics tool for a while now. I tested many services and found some good ones, but they all weren't exactly what I was looking for. I'm happy to say the search is finally over. I found Piwik.
Piwik has anything you would expect from a great web analytics tool:
• detailed, real-time tracking
• customizable dashboards
• multiple sites & accounts
• controls for user privacy
• sophisticated data export
• extensive API's
It's Open Source and can be installed on your own server for free or be hosted by Arvixe for $4+ a month. If you are like me and want it to run on your own server you should have at least PHP 5.1.3 and MySQL 4.1 installed.
I don't want to get in more detail about it because there are just so many features to explore, but if you want to see it in action just checkout the Live Demo.
Other interesting tools for website analytics:
Chartbeat, Clicky, Gaug.es, Google Analytics, GoSquared & Mixpanel