Racket has probably the best macro system out of all existing lisps available to date. Plus it has concept of extensible languages via #lang. If you care about

Racket has probably the best macro system out of all existing lisps available to date. Plus it has concept of extensible languages via #lang. If you care about lisp-style macros and meta-programming that's probably the main reason why I would recommend Racket. Clojure macros in comparison are very ascetic. You can get stuff done in them but it's not a strong feature of the language in my opinion.