I think a job board is a pretty good, typical web app that is a little different than the traditional examples (ecommerce store, CRM, blog).

Job board has multiple different views based on roles (job board admin, job poster, job seeker), a few basic CRUD forms, sorting/filtering/searching (as simple or advanced as you'd like), optional payments for posting fee or premium listings, transactional emails (your job posting is expiring, a new job was been added, etc), optional WYSIWYG editor for previewing/formating job posts, the list goes on and on.