One of the funniest (one may even characterize it as silly) stories in Smith's ouvre is The Door to Saturn, in which the wizard Eibon, author of the bizarre Liber Ivonis, is pursued by an inquisition to (need I post a spoiler alert?) Saturn. The journey is a one-way trip, and the tale makes for the most unusual "buddies on a road trip" narrative I've ever encountered. As in most narratives of this sort, having a riotous time and "getting lucky" (as the kids
But still there were compensations: the fungus-wine of the Ydheems was potent though evil-tasting; and there were females of a sort, if one were not too squeamish.
The Hyperborean tales tend to be CAS' most comical works (the humor being black as the Stygian pits under Mount Voormithadreth, though), The Seven Geases is one extended exercise in gallows-humor (and a clear inspiration of Jack Vance's wonderful The Eyes of the Overworld.
Smith's works were not readily available for many years, but a devoted "cult" following has persisted, and most of his canon is available on the Internet. That being said, pull out the most extensive dictionary you can get your grubby mitts on, and allow the Eldritch Dark to inumbrate you.