The entire series of Deep Space Nine Episodes should be Remastered.
It would be aggreable to see the " Battle of Wolf 359" and the destruction of the Starship Saratoga in greater detail. With today's CGI the battle would have and should have more starships whizzing around etc,.
Seeing more spaceships and even starships in the season 1 thru 3 episodes woudl make the show more fun and " Starfleet " like. The battles with the Klingons and the Runabouts could be tweaked. It would be cool to see always a Runabout in space above the Space Station in exterior shots of DS9 itself.
At the end of the show the Defiant 2 could be redone to make the ship look different. I don't think anyone saw the impact of DVD box set sales when the show ended. It would make DVD sales go through the roof.