A very mediocre sff show--the characters arent really that compelling(they certainly are no Mulder & Scully), the MOTW standalones are the absolute worse and are recycled and stale and they unfortunately litter the first 3 seasons pretty heavily, the science even for a sff is awful. The mythology is its most compelling aspect the only prolem being that a lot of it goes nowhere and the stuff that actually does comes together in a very ho-hum way. I stopped watching it after season 4 and have no desire to see how it ends.I'm mad at myself for staying with it as long as I did thinking it would all be pulled together in some great satisfying manner.
And for an idea of my tastes I loved TNG, DS9(esp its arcs involving the Dominion War), the Xindi arc on ENT and most of S4, The X-Files S1-5, Heroes S1, Supernatural S1/2/4, BSG S1, VD S1/2. I couldn't stand Heroes S2-4, BSG S2.5-4, Caprica, The Event, Invasion, Surface, The River, Stargate Sg1, SGA, SGU, Buffy, Angel, Hercules, Xena, No Ordinary Family,Flash Forward, Alcatraz, Terra Nova, The Secret Circle, VD S3, True Blood, Game of Thrones