I'm more of a fan of blockchain technology than I am of any particular digital currency
Triple entry bookkeeping is a game changer.
Trustless transactions have changed the game of commerce.
Smart contracts have opened the door to an entirely new dimension of self governance.
Autonomous corporations are now possible.
... heck, graphics cards are now being used to MINE THE INTERNET itself for digital assets that can be converted into any fiat currency.
Humans are now employed by a piece of software (bitcoin) and paid by this piece of software to secure it's network (mining reward)
Simply.. I use bitcoin because it allows us to interact with the blockchain, and do alot of things that were literally impossible 20 years ago.