TypeScript, Dart, Babel + ES6, Clojure ... Which one/combination?

So I've been doing my research and apparently coffeescript is dying/dead.
Typescript seems to be coming out on top but is this just from hype and the masses or is it actually (in most respects) the best?

Are there other alternatives I've missed?

I also saw that using a combination of babel+ES6 and typescript could be a great idea - thoughts?
Is it worth going to a strongly typed language at all?
With the given project I'm working on I also intend to bring in rollup.js towards completion in order to minimise the code as much as possible.

Also, how do all of these affect debugging?
In a browser I can just open the dev console and being to play around. But browsers don't have native support for these languages and I do a lot of debugging so I would assume any time I want to change something I'd need to recompile the code and test it that way. Instead of the usual way to debug javascript in the dev console.