Well in my opinion it's a hard pick as there are both limited resources of both so eventually they will be rare commodities, so either will be valuable...
In my opinion, Gold is worth something no matter if it is the year 1000 or the year 5000...So in my personal opinion gold is the better option. Bitcoin is no doubt the best digital commodity, but digital can always be wiped out and thats not a risk I would take if I had the option to own gold over bitcoin!
But as RUEHL mentioned earlier, how can you verify that it is real gold before picking the gold?

This is the hard part. There is no 100% guarentee, but it has a higher chance of having at least some value as opposed to when the power goes out. Since Bitcoin doesn't have much of a physical representation, it's harder to use without the use of electronics. But gold IS somewhat likely to be counterfeited, but it all comes down to luck, mostly. You'll never have 100% guarentees, unless you did it yourself.