First of all none of the answers here answer what are good resources to learn blockchain use-cases, all are just links to tutorials. Second an answer about use cases is obviously going to extend beyond bitcoin so it makes sense to give you a perspective of what other people are doing with blockchains.
We have this list at https://builtin.com/blockchain/blockchain-applications:
12 PROMINENT BLOCKCHAIN APPLICATIONS TO KNOW
1. Secure sharing of medical data
2. Music royalties tracking
3. Cross-border payments
4. Real-time IoT operating systems
5. Personal identity security
6. Anti-money laundering tracking system
7. Supply chain and logistics monitoring
8. Voting mechanism
9. Advertising insights
10. Original content creation
11. Cryptocurrency exchange
12. Real estate processing platform
1. Secure sharing of medical data
2. Music royalties tracking
3. Cross-border payments
4. Real-time IoT operating systems
5. Personal identity security
6. Anti-money laundering tracking system
7. Supply chain and logistics monitoring
8. Voting mechanism
9. Advertising insights
10. Original content creation
11. Cryptocurrency exchange
12. Real estate processing platform
11 and 3 are not real use cases because they require a cryptocurrency and we're trying to look for use cases outside of that. I personally do not like 8 for reasons described in this thread.
More than any of this people have started to use blockchains (not Bitcoin's though) as a way to host DDoS-proof and uncensorable websites. It makes you wonder how they managed to pull that off.
