For an interesting example you can look at:
http://en.literateprograms.org/Quicksort_(Haskell)
What is interesting is to look at the implementation in various languages.
What makes Haskell so interesting, along with other functional languages, is the fact that you have to think differently about how to program. For example, you will generally not use for or while loops, but will use recursion.
As is mentioned above, Haskell and other functional languages excel with parallel processing and writing applications to work on multi-cores.
