Other than Star Trek, I really liked Farscape, Babylon 5 (loved that show) and I'm a new convert to Firefly.
So since the original series, I'd rank them (including some of the Trek spin-offs):
- Deep Space Nine
- Babylon 5
- TNG/Farscape/Firefly (tie)
Agreed, although I think the original OUTER LIMITS deserves an honorable mention.
I saw very little of that for some reason, so I can't really judge. I'll take your word for it, though.