Currently my go-to is: React, Redux, Typescript, CSS Modules (optionally with Less) built/managed via npm and Webpack. The real beauty is that everything is well-encapsulated. If I decide one component absolutely needs to use jQuery for some reason there's nothing stopping me as long as the top-level API is still React.
Momentum, mostly. DT/typings/@types are surprisingly comprehensive and with 2.0 typescript supports strict null checks which was the biggest flaw in my opinion. I've also unfortunately become pretty familiar with some of the obtuse concepts in typescript (e.g. extending module definitions).
I'd love to give Flow a try -- just waiting for the right opportunity.