Been rewatching Deep Space Nine here and there.
SPOILERS
If you want to see just how bad some of the actors truly are on Deep Space Nine, you should definitely check this one out. Not only is it an absolutely horrible Sisko episode about civil rights (what else) but everyone goes without make-up and they do (laughable) New York accents.
Another one is S06E23 'Profit and lace'. It's where they turn Quark into a tranny in order to salvage what's left of the Grand Nagus' authority after he gave females the right to wear clothes. Yes, that's right. Trannies & feminism. :')
(Not to mention parroting all the talking points about getting females into the workforce and doubling the economy, but for some reason they omitted the part where the birth rates would plummet as a consequence. rofl)
S06E24 is also hilariously bad. It's where they decide to send an eighteen-year-old Molly back into the time where she was left stranded for ten years and grew up all alone on an abandoned planet 300 years ago. Apparently, she would be better off there, instead of a Federation clinic, specifically designed to rehabilitate cases like hers. :') :')
Edit:
Season 6 was also the season where they decided to turn Dukat into a cartoon villain and make him the 'nemesis' of Sisko. It resulted in that ridiculous episode where Sisko and Dukat were stranded on a planet and Dukat was talking to himself the whole time. It ended with Sisko ignoring Dukat's mental status and declaring him an 'evil man', after his pride got wounded (once again).
This theme was further explored in S06E17. Where Dukat called up Kira out of nowhere and revealed that he was banging her mother during the occupation, rofl. And then to make it even more preposterous, Kira used the Orb of Time to travel back in time to confirm that her mother was really banging Dukat.
I think DS9 is many people's favorites because it was one of the first TV shows to introduce a continuous story arc (although many of the episodes were still disconnected "alien of the week" style). That's commonplace today, to the point that you won't have any clue what's going on in many shows if you haven't been watching from the beginning of miss an episode, but it was innovative at the time.