Your most and least favourite de Camp pastiche?
Okay, I know the correct answer is probably "none". However, with him bringing Conan into the limelight and sort of filling the gaps in the story to make a cohesive saga, I did read/re-read some of his work lately and I'd say it's not hopeless.
My fave was probably Conan the Liberator. It's not perfect and has some really so-so plot twists, but it is a decent effort at writing one of the most important parts of Conan's life, conquering Aquilonia's throne. It has some insightful descriptions of warfare and politics, battles and logistics are believeable, and King Numedides is described as a scumbag you'll love to hate. Also liked that de Camp wrote Aquilonia as more Rome than France here, I think that fits better in the Hyborean era than late medieval elements.
The least favourite was the quartet of stories describing Conan's hunt for Thoth-Amon (The Witch of the Mist, Black Sphinx of Nebthu, Red Moon of Zembabwei and Shadows in the Skull). Intended to be the grand finale of sorts, it's just a waste of paper, with a very weak plot, mediocre descriptions and totally moronic story logic - I mean, describing the Styx, the equivalent of the Nile, as POISONOUS! Thoth-Amon is reduced to a poorly written Saturday cartoon villain (heck, maybe worse than that - the actual cartoon villains from Conan the Adventurer are more competent) and the final battle with him is very underwhelming. Only Shadows in the Skull was okay somewhat, until you realize that the serpent-men and Lilith are simply copied from REH's Kull and Solomon Kane stories respectively.
A honorable mention for Conan of the Isles - it's sort of final adventure, Conan travelling to Americas, and more or less mediocre, but I liked steampunk Aztecs and the Cthulhu expy there, was fun to read at least.