This is so really hard to say special cause its difficult to explain specialty in short word
Some of them are given below:
Its a type of currency which know as peer to peer currency and this permit to send and receive money without help of broker or third party involvement
Every bitcoin holder can review their account information after sending money or receiving money from their account.
After all kind of transection bitcoin recorded sufficient proof of every client and account holder through different facilities.
Buying and selling process is so much easier than other currency
I think above mention quotation is sufficient for proving that how much special the bitcoin is.
which you say is true bitcoin is a digital currency that uses peer to peer technology that makes data from the contents can not be manipulated and its ownership is very anonym not only that his transaction can also be seen by everyone and have a very high demand and availability supply is very limited, it seems it makes very special bitcoin from other coin.