A lot has been written about Scheme versus Common Lisp and the subject has achieved holy war status much like that of the Emacs versus Vi crusades. I use and am happy with both. I like that Scheme is a Lisp-1 and (theoretically) like that it's a “simple” language. Scheme's continuations are a very powerful and useful feature. I very much prefer Common Lisp macros and I like its large and standardized library. Don't ask me how I reconcile my love of Scheme's simplicity with my love of the large command set of Common Lisp.
So while I'm not interested in enlisting in either side's army, I do enjoy reading why people prefer one or the other. In that spirit, I can recommend this oldie but goodie from 1998 by Philip Greenspun on Scheme vs. Common Lisp. I've seen it before but was reminded of it when I saw it mentioned on one of my news feeds the other day. It's a funny story but even better are the replies to it. If you're a Lisp programmer of any denomination you'll probably enjoy it. If you're a noob trying decide which Lisp to learn I'm afraid you won't find much enlightenment but you may enjoy the spectacle.