Google Analytics

Free, easy to implement and packing enough power to satisfy most general analytics requirements. Google Analytics has had regular additions to it’s functionality and is soon to provide an API.

Clicky

Clicky provides an API allowing you to easily do more with the data collected. Like Google Analytics, it provides a customisable dashboard, but for monitoring on the move, it also has an iPhone optimised interface.

CrazyEgg

CrazyEgg provides a wealth of imaginative visualisation options for your data and also alows you to run specific tests. If you are monitoring site analytics on behalf of a client, there are options to share branded reports with them.

Mint

Mint has an extensible architecture with a number of third party add-ons available. This is a great choice if you want to track more than just the usual website performance statistics.

Woopra

Woopra is a more heavyweight application. It runs through a rich client application and is optimised for monitoring multiple sites at once. In addition to providing real-time monitoring, it also allows you initiate a chat session with a visitor to the site. This could be used to serve a customer service function as well as just analysis.

Enquisite

Enquisite is an analytics package tailored to help with search marketing campaign monitoring. It’s PPC monitoring and alerting can help to detect and act upon suspected click-fraud or problems with how your search ads are served. It also provides rich tools for market trend analysis and geo-specific analysis.

BLVD Status

A fairly new application, BLVD Status aims to provide analytics optimised for search and social media marketing. There are some very clever looking tools for analysing referals for external sites.