Thanks, Ward, for a fun topic!
Keeping it in the family, I really enjoyed some pairings of Salvia and sun tolerant Coleus that I had this year. It probably works best with the more moisture tolerant varieties like Salvia splendens, guaranitica, 'Wendy's Wish', etc. Coleus has so many color and leaf-shape choices that you could really have fun making different color & texture combos.
I don't have any great photos to show, but this is Salvia guaranitica 'Black & Bloom' with Coleus 'Wall Street'.