^ Speaking of one-off characters, what about Captain Jellico? I'm sure that could make out for an interesting series.
Since he's such a tough bastard, I can see Jellico in a Starfleet version of The Dirty Dozen
. He's given command of a bunch of reprobates who have one last chance to avoid prison: volunteer for dangerous missions outside Federation territory, or on the border. They'd use a stealth-style starship, painted black, no transponder signal or ID, and kick ass.