Admittedly character development with a helmeted race is severely curtailed, is like trying to give star wars stormtroopers a personality...but wouldn't a post DS9/Voy series be cool, if it focused on the Federations' interaction with the Breen, Tholians, Gorn and Miradorn (am only including the latter as they were signees of a treaty with the dominion, so potentially may have some sway).
![Very Happy :D](./images/smilies/icon_biggrin.gif)