As someone who is wanting to learn a functional language, it seems to me that F# is a good place to start. I've heard people disparage the lack of HKTs, but some of the other features like Type Providers seem too compelling to pass up.
I've just really started using F#, but the first time I used the Type Providers in FSharp.Data, I was blown away. That and F# interactive make prototyping a REST API client something I can do in minutes.
It's a perfectly good language and a sensible choice if you need the .net interop. But if you just want to learn a functional language, Haskell or Scala provide much the same features and also have HKT support.
