My favorites off the top of my head:
Original Battlestar Galactica
Reboot version however the last season or two sucked
Star Trek Next Generation, stories were well done, effects were great for the time and even decent for today. I liked how there were story arch’s and consistent characters like Q
Babylon 5 ignoring last season
Torchwood
The walking dead was great and different for a few seasons then they started doing cheap trick cliff hangers and weird over the top stuff but regardless first few seasons were epic. Who would have thought a zombie apocalypse story would mostly be about the survivors.
And Buck Fucking Rodgers the first Season was awesome