There is no single best language. Instead, what you get from any sufficiently good programming language is a series of tradeoffs. Haskell, for example, provides the benefits of pure functions (lazy evaluation, composable memory transactions, ability to reason about code) but in so doing it takes away your ability to arbitrarily mutate state and perform IO. That's a tradeoff. Python provides a clean, easily readable syntax that leverages whitespace. But you can't define multi-line lambdas. That's a tradeoff. Most of the languages on the author's list use garbage collection, yet another trade off.

Importantly, it is nigh on impossible to understand the pros and cons of these tradeoffs unless you learn the language first. So get a dart board out and pick a language at random. Learn it well enough to find things you don't like about it. Then learn another language that fixes the problems you had with the first and figure out what you don't like about that language. And so on.

Also, be aware that this process will never, ever end. Because there is no single best language.

Except Haskell ;)