By all means, spriggans large and small!Shocker lizards. I can't believe no one's ever made a shocker lizard. Talk about a great common!
A well-sculpted, well-painted dryad would be great, maybe using the art from the 2nd Kingmaker adventure. The new dryad from WotC is an embarrassment, and the old Black Woods Dryad was not what most people think of when they think "dryad".
Again, by all means, more plants. This is the least well-represented class of creatures in pre-paints.
Urdefhans and morlocks. They're a major feature of Serpent's Skull, and they're totally unrepresented in minis.
The soul eater from Kingmaker 3 could be cool.
Ratfolk and grippli. Kitsune. They'd all be very popular.
How about Blackjack? You already have a sculpt with Reaper, right? Plague doctors? Please, please, pretty please, Red Mantis Assassins? Maybe a summonable giant red praying mantis to go with them? (You could then do a green one as a promo, or vice versa.)
A gypsy with a harrow deck could be cool. Especially if could serve plausibly for a harrower as well.
I'd still like to see a PF male drider as well, since they have a different look than old D&D driders.
And thanks as always for asking what we'd like! :-)
More I look at it the more I love this post.