Considering my oldest character is Lady Midday, she's become the easiest for me to just be obnoxious with, and because of that I guess has become a favorite of mine, if not a particularly frequent "dominant" one. The nature of her obscurity and what it does to her, that she personifies a time of day and ills associated with it, it all makes for fun, most-of-the-time darkly hilarious hijinks.
Other than that, Morphine as of late has taken over my brain, and a lot of it has to do with her connection to Heroin and the other Opiates, to Cocaine, to the deified Civil War vets, and how it all has shaped and continually shapes her.