Hey! As my handle suggests, I'm a huge fan of Babylon 5... and the great Vorlon heretic named Kosh (not the second "Kosh", who was really named Ulkesh but we don't find that out until the books). I also think John Sheridan was the greatest commander in the whole sci-fi genre. But I like a lot of other works too, and my tastes vary widely—my general requirement being that something be done well and with care, rather than half-assed or obviously pandering to a lowest common denominator (I'm looking at YOU, "reality" television). As Kosh would say, "moments of perfect beauty"... (or close enough to perfection, whatever that elusive thing is). That said, I do have a few Guilty Pleasures (Two and a Half Men probably being my guiltiest)....
I was only a recent convert to Babylon 5 however—although I saw an ep here or there in the 90s, I never got into it then. But a couple years ago I bought the Season 1 dvds, and bought just about everything else in B5 canon in short order afterwards (the rest of the series, the movies, books, the short-lived spinoff Crusade). A very intriguing sci-fi 'verse, delving deep into the philosophical and spiritual but not heavy-handed that way—and refreshingly more realistic than Star Trek's Federation utopia, with flawed leadership tackling some very real and difficult problems that will probably never go away despite whatever technical fixes we may come up with. Every character had their warts, and their shots at redemption.
I also like Firefly a lot (and discovered that one post-airing too)—I'll echo that it's a damned shame it didn't last—and am working through Farscape now (looks pretty mindblowing so far). I had seen most of the post-TOS Star Trek franchise shows when they were airing, and have all of Deep Space Nine on dvds.
My favorite show currently airing is Burn Notice.