Pretty much everything, full backups (*.vbk doing File to Tape), except we only send one of our two Exchange servers, only half of our Active Directly related servers, and another single mutli-TB server that never changes we don't send to tape at all. Each of our Exchange servers is on its own dedicated job, and repository, and folder each, at that. Same for AD servers. The old giant never-to-tape server is also in a dedicated job/repository/folder. And some misc. test jobs/repositories/folders.
But really, that's it. I pretty much need to be able to select/unselect items on the fly.