As for "best" Sci-Fi TV that's so much down to taste its kinda useless arguing. A few personal remarks on shows that pop into my mind can't hurt though: IMO, as much promise as Firefly had, it ran far too short to really have any kind of remaining impact. Kinda like Space:AAB, both basically died the same death: they were just too friggin' expensive to produce for TV. Farscape is weird but I quite like it. Star Trek is dead, what's left of the once mighty franchise is so boring even die hard fans are running away. Stargate is a fun show, but nothing really too stunning either. Andromeda stinks. Babylon 5 is still king of the hill...