Actually if you really wanted to be pedantic and look at the actual meanings of the words you are throwing around you could conclude that neither is really analog, but BTC are a lot closer to being analog than USD.

USD usually only come in fractions of at least a hundredth. Every transaction is a multiple of a single cent. This is clearly a digital value.
BTC on the other hand are at least in theory infinitely divisible. Of course in practice you would still store the actual values in a digital representation, but compared to the Dollar they are a lot closer to being at least pseudo-analog.

To get a real analog currency you would have to use gold, silver or perhaps salt as a currency. Technically you would still run into trouble if you go down to microscopic scales or single atoms, but for practical purposes this would be an analog currency.