Sorry for the bump, but I've got two more ideas:
1. A series set between the events of The Voyage Home
and The Undiscovered Country
. It's hard to believe that Kirk & co. served seven years on the Enterprise
-A, yet we only got two movies out of their adventures.
2. A series that does not focus on the captain, but a crewman (or group of crewmen) who are extraordinarily good at solving problems.