I've spent roughly 4 years of midnight-engineering time looking into the cool languages to see if they would make game programming easier or more fun. Haskell, Ocaml, F#, Erlang, Scheme, Lisp, D, Factor, Scala, Python, I've looked at them all.
F# held my attention for quite a while, but now my platform-of-choice has moved away from F#'s design center. (I'm into Linux-based mobile platforms now.) And to be honest, I'm still happier in a C-like language.
I'm depressed. Sure, I learned a lot about fancy language features, but I could have written quite a few games in plain-old-C++ (or C#, or Java or Flash or Basic) in the same time.
P.S. Someone else has done this more impressively than I have. Do a Google Groups search for Brandon van Every, who has had a five year odyssey to find the perfect non-C++ game programming language. I corresponded with him back when we were both interested in O'Caml. Since then he's managed to annoy pretty much everyone by harping on their favorite language's shortcomings. In the end (at least as of six months ago) he'd given up and gone back to C++. I look forward to seeing what he does next.