TNG's O'Brien had one of the most simplest (and mechanically replaceable) position on the ship. Wait to be called, and then teleport. It would be cruel of Starfleet to make a man sit in his room by himself for a shift, where he may not be called at all. Today, people who have remedial jobs like that, where they have to wait periods before being able to work (like help desks), they're allowed to listen to music. Assuming he could put any application/program on his console, what do you think he'd put on there? I say other than your current social media and chat room access, O'Brien has a RTS game on there. Maybe Midevil or Alamo based. He met Keiko on the Enterprise, maybe he has a few ebooks about Asian culture. He definitely has a few technical readout programs (access to the newest specs and whatnot). Oh, and Klingon Digest.