Ulysses31 and Blakes 7 really define sci-fi for me.Ulysses kicked glutes like a boss. I loved it so much because nearly every episode he failed and people died. My favourite episode was the bleak Sisyphus-
I watched this when I was like seven (shortly after Avon shot Blake to death) and my childhood was never the same again.
I've got them both on dvd and watched recently and they're still powerful - blakes 7 in particular is as good as I remembered.