I would pick 3speak.

1. Uncensorable - This is big due to censorship on centralized platforms. New TOS policies now coming out on YouTube.
2. Decentralized - The decentralized nature of Steem allows for other people to change and adopt different front-ends with the same content on the chain.
3. Built in user base - The built in user base makes it easier to acquire an initial audience.
4. Communities - The communities allow for niche's and more content specialization.
5. Dev tools - The dev tools are an essential for building on an ecosystem.