Star Trek: The Next Generation was generally well-done, with interesting charcerters and only a few clunker episodes.
I found Deep Space 9 an interesting concept let down by unimaginative writing.
I found Voyager unwatchable. Janeway came across as an affirmative action bureaucrat. A Captain is a monarch, not a bureaucrat. Patrick Stewart had played Shakespearean kings, and played Picard the same way. It worked. What Janeway needed was a good desk.
Sliders was a really interesting premise that ran out of steam. The same story every week. Yawn.
The X Files also started out well and also ran out of steam, descending in to torture porn.
Didn't watch any of the others, so no comment.