What Lisp should I learn?

I already know Scheme (read SICP, took the class, got an A, wrote a logo interpreter in Scheme, wrote a Scheme interpreter in Python, etc.) but I haven't touched it much in two years. It seems to be great for computation, and I can certainly see where it would be a perfect fit for artificial intelligence, but I can't imagine using it for applications or even simple scripts.

So tell me /prog/, what Lisp dialect should I learn or at least what are the pros and cons of each?

>>5
Clojure attempts to be convenient, as to provide lots of syntactic sugar and some heavy-weight features to provide some traditionally simpler ones (like mutability). Its reliance on STM is an interesting experiment on an Lisp language, but other decisions such a s giving :keywords such preponderance, the seq abstraction which yields sometimes surprising results (don't mix vector and list functions, but don't ask me how do you tell which ones are which), and many ways to define a record-like thing are somewhat off-putting.

On the other hand, I'd be surprised if 1000-pages-spec Common Lisp didn't share many of those same weaknesses. And good luck finding any libraries for the JVM Schemes.

The stack traces do suck, though, and that's a damn shame.