I watched TNG when it originally aired, bailed halfway through Season 1 because it was crap. I started watching again with Season 3, which kicked ass! Assuming that I'd missed something in Season 2, I went back and re-watched it later, but it turned out to have been A VERY GRADUAL IMPROVEMENT. Season 3 is the first good season of TNG.
When I get back to the USA, I'll watch DS9 in its entirety.
If anyone likes reading Star Trek stuff, Peter David has a series which is pretty good, New Frontier, featuring many of the popular recurring characters from TNG and DS9.