Stargate (any of the TV shows) can't really come back as was - its been too long - but it could certainly do with a reboot with a new show.
Same for Babylon 5 (though it's a bit overrated by my fellow sci-fi fans), Firefly (ditto), Sliders (although they'd butcher this with cringe, like they did with the new Quantum Leap), and heck even things like Space: Above and Beyond.
As for more modern shows that could come back in the same form: Dark Matter (was pretty fun - got cancelled just as it looked like it was going to hit its stride), Black Mirror (seems to have been mothballed for now), and Red Dwarf.
Oh, and the big one: pre-Kurtzman Star Trek. Just reset the timeline, apologise to fans, and pretend everything after Enterprise never happened.
