Michael Piller was the head writer until mid-season three, when he stepped down on both DS9 and VOY to become just a Creative Consultant. He had been a big force on TNG, and was the reason TNG became so good in season three. Having him co-create the series was a very wise move.
Ira Steven Behr was on the staff from the start, and became the new head writer when Michael Piller stood down. He stayed with the show for the rest of its run. His Ferengi episodes were a bit strange, but his guiding hand ensured that the show continued to build on what came before. And he liked Iggy Pop too so there you go.
Robert Hewitt Wolfe was also on the show from the start, but left at the end of season five. He often wrote with Ira Steven Behr, and they often wrote amaing things together.
Peter Allan Fields was on staff for seasons one and two, before wanting to leave. He wrote The Inner Light on TNG, and Duet and Necessary Evil on DS9, amongst others.
At the start of season three, when TNG finished, Rene Echevarria moved over to DS9 till the end of its run. He was another very good writer, contributing Nor The Battle To The Strong, Children of Time and Chimera.
Ronald D. Moore also moved over to DS9 in season three, and was there to the end of the series. Ron had a hand in continuing the Klingon legacy he had helped to create on TNG, and also wrote stuff like In The Pale Moonlight.
Hans Beimler finally joined the staff during season four, despite having written some scripts for TNG and DS9 before. He was also there for the rest of the show's run. He would later become Ira Steven Behr's writing partner for the show after Robert Hewitt Wolfe left in season five.
David Weddle and Bradley Thompson joined the show in season six after Rober Hewitt Wolfe left in season five, and again were there to the end. They were pretty good, but were far and away much better on the Battlestar Galactica series Ronald D. Moore ran.
I'm not sure if that little infoburst is anything you wanted in particular, but I've read the DS9 companion that many times that these things just stick.
Jadzia being killed off was more of a necessity, as Terry Farrell (who played Dax) wanted to the leave the series.
DS9 is a brilliant series. The first season is a bit run of the mill, but there is a big step up in quality in seasons two and three. By season four, the show was more consistent, and then season five onwards just had the writers stirring the pot of everything that had come before. And it was glorious.
VOY season three is, for me, one of that series weakest seasons. I sort of understand where you're coming from though as the show went through its own changes during season three. More CGI was being used, and more action oriented endings were used, whereas the Kazon and Viidians were left behind.
Oh and I loved Lost. I loved it all the way through to the end. Seasons one and four were when I was the most gripped, but I lived on it for a while there.
