Which functional language?

I want to learn a functional programming language from the Lisp dialect but I'm not sure which one to pick. I want to be able to do practical things with it so I was thinking about Clojure. Does /prog/ have any suggestions?

>>2
So would you say that Clojure is worth learning? I use CL and I was just looking at Clojure a little, there are a bunch of things I don't really like about it (Lisp-1, no TCO, minor annoyances like () evaluating to true) but it does have some neat features. I guess that it's biggest advantage (arguably) is that it runs on the JVM, isn't it?