Had to vote that I love them both and think they're both great shows overall (thus I voted the top option), though the edge would go to DS9 I think.
TNG is what got me into Trek and really drew me into the world, so it'll always have a special place to me, but I do really like the characters and there are a lot of good stories. DS9 really fleshed out that world more, and gave an equally good cast, many more story arcs, and gave us the Defiant.
TNG and DS9 are televised Trek's golden age. TOS was occasionally good, but kinda meh. Then you have TNG and DS9, then Voyager which is mostly good but started to go downhill, and then you have ENT. A rise, a peak, then a fall.