Farscape is good for a lot of reasons, but I'll go into a few of them
1. The aesthetics. It was the Jim Henson company's biggest production in years, and it is well-designed. There are weird influences everywhere - Russian futurist designs in Peacekeeper stuff, organic influences everywhere, and a lot of bdsm-looking stuff. It's really fucking over-the-top and colourful and comic-booky and slick.
2. The characters. So the basic premise is a brilliant astrophysicist stranded in a distant part of the universe on a ship full of escaped alien prisoners and they fuck shit up and get in adventures. What this does not tell you is that over 4 seasons of isolation and insane stress, this astronaut unravels and slowly goes fucking insane. He starts off as an all-american hero, but by the last season he's strapping home-made nuclear bombs to his chest, writing math equations in his blood, and paints a quasi-sentient repair robot red and white and blue and teaches it to sing the 1812 overture because he's so lonely that that is his only friend. Another main character is basically space Saddam Hussein. People say the first season is weak plotlines, but I disagree, mainly because in the first season, all the main characters are still criminals - two anarchist terrorists, aforementioned space saddam hussein, fascist enforcer, et al - are still mistrustful and at each other's throats all the time, and it's a fun dynamic. When they start working together, the series introduces even more crazy and unlikeable characters like schizophrenic/pathological liar magical being of soul Stark or or making former villains into awesome mains.
3. It goes to strange, awesome, dark places. It has one episode that is entirely sa story told by Crichton as an excuse for losing all his money, and the story becomes more incoherent and cliche as he gets drunker telling the story. It has perhaps my favourite science fiction time travel episode (Different Destinations) right up there with City on the Edge of Forever. It has a Looney Tunes episode. It has an episode where the lead mysteriously goes back to Earth only to find it was all a dream etcetera. So in the next season he has an episode where he mysteriously goes back to Earth again, the episode's title i 'Won't Get Fooled Again', and he spends the entire episode trying to break shit and do outrageous things to try to fuck with the system. This is also a symptom of him going fucking nuts. The fourth season's climax is pretty much entirely about the crew trying to sabotage an inter-galactic peace conference. I don't want to spoil shit for you, but characters go to strange places and then form crazy plans and I like it. And one recurring villain is just a straight-up wizard.
4. I enjoy the humour the show has. It's self-referential and kind of dorky but fuck you it's also dark and strange and funny and I like it. The characters never really solve problems - indeed, each season generally ends up with them destroying something enormous and carving their way through the detritus to try to save their dumb asses.
5. It gets cooler with each season, and it somehow treats the increasing stakes and increasing levels of bombast with just the right notes to keep me happy.
6. Did I mention the BDSM? Because Farscape's weird and kinky and teasing eroticism is really unique in Western televised science fiction, and it makes it stand out among the crowd. It's a big thing in the series. Characters lick each other, or get tied up and date raped by alien commanders that keep evil pheromone-producers in their cleavage, and everyone likes wearing black leather. I've said 'dark/strange/funny' like eight times now, but that is basically the key to everything I like about this show.
7. Nerds are also apt to like it because it has the best romance in televised western sci fi that I can recall. At least, if there's a better one out there, I'd be happy to be informed, because it certainly beats Delenn and Sheridan. And one of the better bromances, too.
Now, Farscape also has some bad, bad episodes. Like, truly atrocious. The second episode of the series is one of the most boring pieces of shit I've ever watched. I dunno how much you liked Firefly versus how much you're antagonizing nerds, but for me, I thought it had some weak episodes, like the one where River's burnt at the stake or The Message, but only one really bad episode, Heart of Gold, the one about the whores. It's a terrible piece of television, with maybe one or two moments or features that are good in a generally awful mess. Farscape has some episodes that are so dull, illogical, and pointless, that they make Heart of Gold look like The Wire. Farscape is like that girl with curls from the children's rhyme - when it was good, it was really, really, good, and when it was bad, it was awful. But you watched DS9 and liked it so I can't see this bothering you.
ps the locket is really good
and jeremiah crichton isn't even the worst episode of season 1