Since you asked about Lisp: Clojure is a modern and currently popular form of Lisp. This talk by its inventor, Rich Hickey, gives a clear and entertaining overview of some of the language's strengths from a high level (more philosophical than technical): http://www.infoq.com/presentations/Are-We-There-Yet-Rich-Hickey Just to mention one strength of Clojure: like other functional languages (e.g. Haskell, Erlang), it steers you towards building your program out of functions that don't have side effects. This could become increasingly important as the number of processing cores in our computers increases, since to take better advantage of the hardware you need to be able to process data in parallel. If your functions don't have side effects parallelism becomes more manageable. Other strengths of Clojure include: a regular and predictable syntax, efficient immutable data structures (see the talk) and easy interop with Java libraries (since it runs on the Java VM).
In my opinion, Clojure could be the perfect modern Lisp if it WASN'T so tied to the JVM. See http://lisp-univ-etc.blogspot.com/2011/11/clojure-complexity.html and http://www.loper-os.org/?p=42. I'm not saying that cool stuff can't be done in Clojure, but it only appears to be the modern Lisp it wants to be.