1. Jesus - wouldn't it be interesting if the Second Coming was actually just him coming 'back from the dead' (again) because some random guy willed it so?
2. Douglas Adams - there has to have been inspiration for at least one more Hitchhiker's book from him.
3. Isaac Asimov - jerk never finished the Foundation series before he died.
4. Mohammed - let's be honest, Islam needs a leader to smooth relations with other cultures. Who better than the prophet himself? I think he'd be able to clear up a lot of issues.
5. Saddam Hussein - not really, but how freaky would it be if he just kinda showed up again a few weeks after his death? Weird.
Jam it back in, in the dark.