I'd have loved an Excelsior series, but it's really too late now I think.
Here's what I want n no real order:-
1. A show set sometime during the WoK-TUC era.
2. A show set in the JJ universe, but with more thoughtful sensibilities rather than Star Wars action.
3. An interesting cast of characters, each with a fleshed out back story. Say what you will about Enterprise (I sure have), but the one thing it had over TNG and VOY is that I actually cared for the characters and believed their chemistry... Heck there WAS chemistry.
4. No holodeck, no technobabble and no religibabble.
5. Ships that feel massive and don't zip around as if they're fighter planes. That was the only downside of DS9.
6. Equally space should feel massive, a dark abyss full of mystery and marvel. Traveling to a star system shouldn't feel like a routine visit to the corner store, it should feel like an adventure. For some reason post 80's space opera makes it feel rather unimpressive (just recently watched Star Blazers for the first time and damn if a 70's cartoon can make space feel big, so can modern Trek).
Good plots of course are obvious.