Before discovering Python (the most fun way to program!) in 1999, I studied various obscure programming languages:
Haskell, OCaml - functional languages, mathematically pleasing but not very practical for normal applications. Erlang is also in this family, but has core support for concurrency. And I hear it has even been used in real world!
Prolog - "Logical"/AI programming, for deductive problem solving. Never found any use for this.
Lisp, Scheme (still use it in the form of emacs lisp) - actually a very useful family of languages. A bit like Python, but with an awkward syntax. If Python (and Ruby) suddenly disappeared from the world, Lisp would be the best contender for the language supremacy. People often refer these languages as functional languages, but they are not. That's probably why they are used in production applications.
Ruby - A rip-off of Python. It's big in Japan, apparently. The Ruby crowd likes to tout how much better it is than Perl, while they really should be comparing it to Python. An