The first CS class at The University of Texas used to be taught in Haskell. I'm not entirely sure why, but probably to start everyone off in the same place in a seriously formal language. That was my first serious programming experience and gave me severe doubts as to whether CS was for me. I of course made it through. Now I don't remember any of Haskell, though I'd like to check it out again and see what those monads were all about.