Our current challenge is boolean searching our own candidate pool and custom reporting
Must-haves: 
OFCCP/Veteran/EEO survey/reporting
customizable prescreening questions with knockouts based on job requirements build on to the application.
interview templates with quick visuals
custom workflows
mobile application
careers page
candidate communication based on candidate not the job - quick view of all the jobs they are attached to
Candidate relationship management
offer letter templates
job aggregation to multiple sites without company accounts