The most important thing in my opinion is its scalability. The modern generation still take care too much about "scalability" and probably that is the reason why they still prefer to stick with the traditional centralized systems. EOS has the potential to scale millions of transactions and that is why it comes at par with the traditional system yet it is decentralized. It also separates authentication from execution and that is where it becomes even more unique.
It is also very very flexible. It can freeze & fix broken applications. Generalized role based permissions and web assembly are the key features of it.
The most important aspect from a user's point of view in blockchain space is transaction fee. I am sure almost 90% users do not like to pay the transaction fee and those who make transaction daily and in good volume it is a major cost form them. EOS completely eliminates transaction fees.
In EOS one does not have to remember long cryptographic keys and it emphasizes on true user accounts with username, password and account recovery option. So the usability is greatly enhanced in EOS.
If you remember, in past high performance dApps could not able to perform because of the limitation of infrastructures. This limitation is perfectly addressed by EOS in many forms. EOS offers that infrastructure which can support high performaing dApps. Because of its high scalability, now the dApps can function perfectly, so the performance of dApps have also got enhanced greatly.
All the above points makes EOS unique among the blockchains for sure.
Hope this helps.
The rapid block time they have, similar to STEEM. The possibilities of smart contracts like EOS. No transaction fees for actions, just need enough CPU(like RC in STEEM). They took what they liked from other chains and developed their own. Plus, Dan Larimer who worked on STEEM is the founder as well.