Distributed file storage: Sia [1] and Storj [2] are both using blockchain tech to form a dropbox-like atmosphere where you can rent space for as little as 2c/GB. Renters can rent out their extra storage, while miners can mine and sell their units or use them on file storage to pay rent for their data.
Decentralized Content Platform: Steem-it. Very interesting concept here about compensating content creators with the currency that the platform surrounds. It bears somewhat of a resemblance to Reddit. [3]
Private yet fungible cryptocurrency: Monero (XMR) is a cryptocurrency on the rise that has privacy baked in, with the ability to opt-in to making your transaction public. It uses Ring Confidential Transactions [4] to mix the transactions and reduce the chances of the participants being identified to an almost 0 chance. It is ASIC resistant [5], has solid governance and dev team, and can even be used on hardware wallets like Tresor with a bit of hacking [6].
[1] - https://www.sia.tech/whitepaper.pdf
[2] - https://storj.io/storj.pdf
[3] - https://steemit.com/steemit/@panenka/what-is-steemit-and-how...
[4] - https://eprint.iacr.org/2015/1098.pdf
[5] - https://monero.stackexchange.com/a/138
[6] - https://forum.getmonero.org/4/academic-and-technical/2495/ex...
Disclosure: There could be some bias, because I'm long on all of these except Storj, so I'm including sources that hopefully will allow you to make your own decision without me being preachy.