I actually really like Haskell though I have never had the chance to do a project in it. I appreciate the strong type inference and its flexibility in static typing. I occasionally find myself frustrated my C#'s limitations around complex typing. Like that there is nothing close to existential types and you can't create more complex generic type constraints.
Scala seems cool in what little I have read about it. I really respect Martin Odersky who designed it. I'd like to learn more about it, until I do I can't speak much to it.