One possibility would be to have a gruff captain, and crew that don't get along with each one pursuing his or her own agendas sort of like Battlestar Galactica.
So, Terran Empire then
There are other concepts.
1) A Sipowitz style captain (NYPD Blue). Basically a stand up good guy but often rude, crude, clumsy socially, and abrasive.
2) A Vic Mackey style captain (The Shield). A very dangerous and deeply flawed man who is ultimately trying to do good things (take bad guys off the streets) but is willing to use the absolute most evil techniques possible to do so.