I like React, Redux, CSS Modules, Babel.
I like the ideas of TypeScript and Relay, but don't use them because of the implementation architecture quality. Looks like they were not implemented by web people...
React because of immutable and declarative. Some for Redux.
CSS Modules because of webpack and modularity.
Babel because because I don't like the TypeScript implementation.
And I really like flexbox. So cool ;)