While all turing complete languages are equivalent, some are more amenable to achieving the goals of the FP thesis than others.
Extremely poor: Java (http://functionaljava.org/), Python, Ruby, JavaScript, C, C++
Moderate but still poor: Scala (http://code.google.com/p/scalaz), C#, F#
Practical: Haskell, Clean (pure, lazy functional languages).
There is nothing in between (this is an implication of the central tenet of FP!). We need a revolutionary leap to discontinue the overwhelming, costly mistakes we currently endure and often insist on!
This is unfortunate, but this is true. Let's face the hard facts. Let's understand What Functional Programming Means.