I learned JavaScript from The Definitive Guide before The Good Parts came out, so maybe my opinion is skewed, but I don't think Good Parts covers enough material to be useful on it's own (Good Parts doesn't cover DOM APIs at all, for example).

I can tell you Definitive Guide also sat next to my desk to serve as a reference for a long time, though most of the same material can be found on https://developer.mozilla.org/en/JavaScript http://www.w3schools.com/js/default.asp and many other websites.