For me the decentralized nature of bitcoin and the thought of being able to send coins to anybody in any part of the word, no third party, no regulation(specific amount), no bullshit is mind blowing.
Well for me, this is the list I really love about bitcoin, I put it in an order.
1. Limited total amount. If I remember it correctly, the total amount of bitcoin that can be mined into this world is 21 million bitcoin. So it will be different from fiat currency that can be produced as many as central power wants, because I doubt the money that is going around in the world now are backed up by assets like gold.
2. Decentralized system. This is a cool things, because bitcoin is not controlled by anyone in this world, anyone can have it and use it without some central regulation.