Babylon 5, hands-down!
Classic Galactica and the New Galactica also are quite good.
Farscape was also great.
There was also a short-lived series called
Space Rangers that could have been a contender.
Classic Star Trek was great, though I didn't care for any of the new ones that much, though the newer series' each had their moments.
I have not watched Enterprise...
"Beware the form-fitting black armor-clad Drow hottie with twin Mineral II Greensteel Khopeshes!"
"Liella d'Orien says, '"You're the fool, Devil. -- Witness the power of this fully ARMED and OPERATIONAL Titan!"'"
----------------------------------------------------------------------