That's a matter of perspective.
I like Babylon 5, but I've never considered it a "great" show. But there are folks who think it's the best science fiction show of all time. Whereas I don't think it was even the best science fiction show centered on a space station on the air at the time (that would be Deep Space 9). The story is interesting, the real strength of the series, but the acting (and the production) is so bad at times that it almost ruins it.
Farscape, on the other hand, was one of my favorite shows of all time (any genre). I didn't start watching it until the third season (I think), assuming it was crap because it was on SciFi and had muppets. Once I got into it, I started watching and recording the reruns and eventually got to see the entire run of the series. There's some bad stand-alone episodes strewn in, but all-in-all it's a really strong show from beginning to end, and it has pretty much everything you could ever want in a show - action, drama, comedy, romance, mostly (really) good special effects.
So I think my vote's pretty clear. But I think others will disagree.