An animated series is really the only thing I'd be interested in at this point.
I'd also be interested in another animated series. Our graphics technology is far more advanced than it was 40 years ago,
A few other ideas:
1. Some of the more popular novels made into episodes
2. A series featuring Hikaru Sulu following his promotion to captain
3. A series featuring John Harriman following the events of Star Trek Generations
4. Perhaps a strange idea, but there could also be a series that showcases the more interesting adventures from various ships instead of being focused on a specific crew
Expanding on my idea for a 30th century series: it'd be cool to see the crew of an Enterprise
explore distant galaxies and different points in time instead of mere star systems.