Lost in Space was unwatchable crap. Even as a kid I hated it.
Voyage, LotG and TT were OK but I didn't feel the urge to tune in every week.
Buck was sort of OK but Twiki was just too annoying.
Galactica was good at the time.
Man from Atlantis was poor and Logan's run was just about O.K.
The Invaders quickly became tedious and repetitive.
Space 1999 still looks great, but the science was crud and the stories went downhill in the second season.
UFO was very good.
Blakes 7 was excellent despite looking very very cheap. If only Gerry Anderson had made it...
Twilight Zone, The Outer Limits and Night Stalker never appealed to me.
I have to be wary of hindsight, as none of them have stand up particularly well now, but I did think most of them were utter tripe at the time !
It makes you aware how good TOS was for its day, and even that looks rather cheesy now.