How is Clojure? Common Lisp? Racket?

I've only ever used R5RS Scheme so with that in mind how do the main Lisp dialects today compare?

I want to write a web facing application in Lisp to see how it "feels". For the record I don't think I ever had as much fun programming as I did when I was using Scheme and I want experience that clear and concise magical thinking again.

Write your own Lisp. Thats what Paul Graham did and now he runs the site which provides /prog/ with most of its content!