I will go with bitcoin as it is not only an investment but also a best currency which can used anywhere, gold is something you can only hold cannot be used like a currency.
Just be realistic. Other than a few online exchanges, how many places accept Bitcoin as a currency? There are relatively few online stores such as TigerDirect which accept Bitcoin payments (and the number seems to be declining). On the other hand, you can easily convert your gold to fiat using any pawnshop and make the payment.