Definitly Bitcoin. Even if there is a apocalypse, I dont think that every single Server in the Bitcoin network is going down. As long as this isnt hapenning my Bitcoins are safe. Nobody should be able to steal it as well.
With gold on the other hand, a lot of people are trying to get some gold in their hands when a apocalypse has happened. I mean Dollar, Euros and anything else is gonna be worthless and gold would be the fall back currency aside of the classical bartering.

Your Bitcoins would be safe stored / locked away. The only question is, how much will a Bitcoin worth after a apocalypse? And does anybody accept this currency for exchange / trading then?