When building web reservation systems for hotels one saying of Steve Krug remained a guiding rule- "Don't make me Think!" In other words I should be able to find the content I need immediately.
This applies to BI and Analytics just as much. Users need dashboards, visualisations, drill-down reports in the context of the workflows and application tasks they use in their everyday jobs.
The best visual is the one that allows a normal human with understanding of a business system to quickly see how the visuals match up with the system, learn new unexpected things about the system (business) if there are any, but mostly just match up with their innate understanding of the business.