I don't know what is a best word to use to say about Bitcoin.
Magic internet money 
On a more serious note: all of the terms you mentioned work just fine. There's more than one way to describe Bitcoin.
Haha, Magic internet money.
Undoubtedly, I like this wording, which I will add to my vocabulary of funny phrases.For me, it is not so important what word to call bitcoin. Virtual, digital or cryptocurrency. I think the fundamental factor is what opportunities this currency allows you to get. But I, perhaps, after LoyceV, will now call Bitcoin magic internet money.
