I spent some time learning a decent amount of Common Lisp last year. Nothing fancy, but I'm comfortable using quicklisp, playing around with libraries, modelling stuff, etc. I've read through PCL and ClTl2 (though unfortunately, not PAIP (not yet!)).
They've been a bunch of other new (as in, the last 7 years ?) languages that I've looked at off and on. Gone through a few tutorials, read (no, lightly skimmed) some suggested material (learn you a X, learn Y in Z minutes, etc). I love Common Lisp (enough to simply call it "Lisp" to the exclusion of the gazillion varieties of scheme (and yes, Clojure too (!))), but yeah, the lack of libraries does get to be a pain point.
So someone suggested I try Clojure, but I'll pass. I don't want to look at stuff ending with "))]))})]})". If I need reader macros for hash-tables, cl21 has it, though I think rutils should suffice for a nice superset of useful library add-ons (OTOH the Overtone/Quil/ShaderTone combo does make me salivate, and I definitely will check try them out at some point).
If I have to work with the JVM, I figure I might as well learn something new/different that isn't trying too hard to be Lisp. Hence, Scala. I may regret this later (but how bad can it be). I hear people loved the MOOC on it last year, and looks like I just missed the one this year, but this being Coursera (yay) I can still do the videos and the assignments.