For those that don't know (probably smaller on here then elsewhere but still):

HtDP: How to Design Programs SICP: Structure and Interpretation of Computer Programs PCL: Practical Common Lisp ACL: ASCII Common Lisp PAIP: Principles off Artificial Intelligence Programming OL: On Lisp

Personally I'd probably go for PCL because it's... practical.

OL is pretty awesome though, I wish someone would reprint it in English, I have a self printed copy but I'd very much like to own a proper one!