Hey, I just got a great idea for an animated series:
Star Trek: Mirror Universe
The Mirror Universe would go from the 22nd century (Captain Archer's time) to the 24th century (The Next Generation, Deep Space Nine, and Voyager) The reason why its a good idea is the actors have aged since those television series were produced, but we can still use them as voice actors for animated characters. The thing about the Mirror Universe that's different from all the rest is that the main characters from all the regular series are more expendable. Expendability creates suspense, since the viewer doesn't know who is going to live and who is going to die, the sense of danger and tension is all the more greater. We need a larger cast of regular characters of course, the actors would have contracts that specify that they continue to get paid for a certain amount of time even if their characters get killed, and if a particular actor is too expensive, a sound alike can more readily be found than someone who sort of looks like that character in live action.