Excellent book to discover and learn Lisp, maybe the best one actually. It covers all aspect of Lisp and provides lot of examples code based on games. This is somehow more fun than the math example of SCIP (even if this is another great book I deeply appreciate too)

If you enjoyed this little taste, you should get the book. It's really fun. There's a lot of code in it, and although it uses games as the subject for the examples, the code is definitely not fluff. It's been a year or two since I read it, but I recall that there's a bunch of graph traversal and search programs and even some low-level HTTP code.

Ruby Rogues podcast discussed it with the author (1hr mp3, transcript available): http://rubyrogues.com/043-rr-book-club-land-of-list-with-con...

Incidentally, the author (Conrad Barski) says in that discussion that Clojure is his favorite Lisp now and he finds it much more elegant than Common Lisp. I have a similar background (CL programming, now doing Clojure) and I agree.

Land of Lisp was how I first got into Lisp - I was hooked already before finishing even a third of it.

For production code, I ended up abandoning Common Lisp for the most part in favor of Racket, simply because of its library support and compatible, scoped dialects, but the principles are the same in either case. I'd actually recommend starting with something less 'batteries included' if you have the patience, because it makes it easier to see the fundamental beauty of the language, without getting distracted by something as "irrelevant" as library support.

Some people say that Land of Lisp makes it hard to develop 'useful' applications afterwards, but for that, I think Practical Common Lisp is a good secondary resource, and it's easy to skim once you've completed Land of Lisp. Land of Lisp is much better as "Lisp Propaganda" - ie, for someone who's interested in giving it a shot, it does a good job of selling the Lisp paradigm as a whole philosophy, even if it doesn't have space to cover all of its practical uses[0].

[0] I won't sell it short, though - it does a good job for that too... several of the games it implements are non-trivial.