jdrakeh
Front Range Warlock
Best? Maybe for the months of June 2000 and July 2000.
Whenever somebody here (at ENWorld) asks about 'best of 3.0' or 'best 3x monster books', the original CC still makes the lists of several posters (as does the corrected CC Revised). It had its flaws, sure, but I think Diaglo is way off base suggesting that it was "horrible" — as are you, suggesting that it had no real lasting appeal after the month of its initial release.
That said, people do seem to enshrine it as a 'best of' because of the illustrations, flavor text, and monster descriptions — not because of the mechanics. In that regard, I think it's a stand out example of mechanics not necessarily 'making' a product. For its mechanical foibles, CC sold well enough to warrant a reissue and still earns accolades from gamers on this very forum.