javascript: it's "like scheme with syntax", necessary anyway for cool web apps, expressive, has closures, lexical scoping, and with Rhino you can access any of the Java libraries (without writing Java code) and run it efficiently on any platform (for server-side or desktop apps). It's really the do-it-all language.
Oliver Steele has written a great functional programming library that adds list comprehension and textural/literal lambdas to Javascript.
I keep meaning to play with that, but I always seem to have something else (like work) that I need to worry about.
Analogy alert: I kinda see functional programming as like giving up smoking. It may hurt a bit at first, but it's much better for you in the long run, providing you don't annoy everyone by continually letting them know...
