Hard to pick a winner from those I have seen.
Maybe Domme, a hilltop walled medieval town with stunning views of the Dordogne directly below the ramparts?
Loubressac or Autoire, both visited with Nicholas?
Or Beynac-et-Cazenac, creeping up the cliffside beside the river and dominated by a fairy-tale castle, once besieged by Richard the Lion Heart?
La Roque-Gageac with cream stone houses and brown-tiled roofs, clinging to the riverside not far from Beynac, or Carrenac where I stopped randomly, probably for coffee, only to discover it has an eleventh-century priory.
Each one perfect in its own way and so different. Mmmm...
No, I know. Saint-Guillem-le-Desert is my favorite. Matt and I went there from Montpellier, and I went back with Nicholas to do a walk in the valley beyond. Favorite so far, anyway.