We use the Custom Fields plugin. We added a custom dropdown field called "Customer Satisfaction". For now, it has choices of Happy, Unhappy, and N/A. However, there are some others we may be adding.
Some of our FogBugz projects revolve around external customer interaction, so for those we want it to default to "Happy".
Many of our projects are for internal use. Customer Satisfaction should ideally be N/A for this by default. However, I can't do that currently. The default value of "Happy" gets set on a lot of cases that do not have any customer interaction.
It would be nice if the default value of this field could change based on the Project.