At the risk of getting heavy objects thrown at my person, I would call this the best show - certainly the best SciFi show - on American television in the early/mid-2000's. (This is a thing called an uneducated opinion. You are welcome to have your own.)
Out of the fog of reality TV shows, procedural shows, sit-coms and SciFi shows that translated 'aliens' as 'humans with weird bumps on their forehead,' Farscape appeared. Wonky and chaotic and sexy and hilarious, this little oddball show gained enough of a following that, when it was suddenly cancelled despite having been promised a fifth season, fans were so vocal in their outrage that it was brought back in a mini-series.
The show takes a standard fish-out-of-water scenario - in this case, an Earth astronaut shot through a wormhole into outerspace - and shakes it up, turns it on its head, then displays itself to you like an acid trip. The plot, and here I quote Wikipedia, involves "features a diverse ensemble of characters who are initially escaping from corrupt authorities called Peacekeepers. The protagonists live inside a giant space-dwelling creature named Moya, which serves as their ship."
Farscape is weird. The aliens are intricately designed, the episodes well-plotted, and there's psychological torture and bad luck in abundance. There's not, comparatvely, a whole lot of shooting and explosions. (But when the explosions happen, they are almost artistically crafted.) It's also ridiculous, which is how you occasionally get aliens in Hawai'ian shirts and men in tights.
The writing is complex - in a good way, the way that means you need more than a few brain cells to follow along - and there is no standard, boring pattern that each episode is hammered into. It also addresses, indirectly, the ugly issues of ethnocintricity and corrupt authority.
The acting is superb. The characters all have their own personalities, strengths, faults, motivations, complications, and moments of pettiness. The show also boasts some of the only convincingly badass women I have ever seen on television - ones who look like they have the mental and physical strength to back up their words, and are no more or less interesting and faulted than the men.
Also, there are muppets. (Really.) They move, emote, speak, and interact on the level of a professional actor, and it is testament to the talent of the puppeteers, voice actors, script writers and supporting cast that you occasionally forget they are not human.
Plus, the show is hilarious. (It would have to be, with all the time it spends messing with the poor characters' heads.)
In short, Farscape is a witty, chaotic, mind-bending breath of fresh air. And I leave you with the clip at right.