Thought provoking OP. I like to see a smile too and thinking about this I tend to go back to the smiley ones. Now there is smiling because you are having some banter and then there is the smile you get which is welcoming (ie she’s genuinely pleased to see you when the door opens) and then there is the smile you get when you hit her sweet spots. All different drivers and all delightful to experience.
I think I can name a few (Paige White, Lucie Bee, Woofie, Riley Lee and Kylie all spring readily to mind in the East Mids) of course, remember YMMV.