If you have the money to spend on a real time analytic system,  a step above and beyond Google Analytics, I recommend either Omniture or Hitslink.  Listed below is a quick breakdown of the differences between these two companies.  Click on the images to see them on a fuller scale.

Omniture:

• Costs more
• More comprehensive reporting with additional drill down and customizable reports
• You could eventually use this to replace GA entirely since it has a similar interface and functionality
• More complex, higher learning curve
• More time-consuming installation that requires more customization
• Provides an integration of Adobe Suite including consolidation of PPC management
• can potentially integrate additional data sources
• can query the data warehouse for highly customized reporting

Hitslink:

• Costs less
• More high level, easy to understand reporting with capabilities for custom reporting
• Used as an addition to GA for top level real time KPI reporting
• Easy, intuitive, lower learning curve
• Simple and fast installation
• Doesn’t provide consolidated paid search management, but does allow for campaign tracking
• Doesn’t provide data API for additional data integration
• Can’t query the data warehouse
• Can create new funnels on the fly that are applied to historical data (below is a snapshot of an example  funnel page)