I think a Twilight Zone style show could be great. A new week, a new crew, new setting, and characters. It could deal with a Klingon crew, a Romulan Crew. You could go all the way to the Delta Quadrant and have a Borg only episode. It would be cost effective, since there would be no standard crew to pay, and you could get big actors to guest star more often. Also, it would be a totally fresh approach to the series. Each episode would be a self contained episode, except for the last few. The main story could collide into a trilogy for the finale.