What plot holes/ dodgy special effects are forgivable and which make episodes incurably naff ? I offer the shoot out in Hostage (that bit of string ?!) as my own sacrificial candidate.
I would say that depends to a large degree on the importance of the special effect/plot hole to the episode/charcaters in question. That silly lightning flash when they clink cups in Warlord is a momentary thing and therefore forgivable. Travis wrapped in sheets is supposed to be convincing enough to fool the Liberator crew and therefore renders the entire episode dire. The silly machine with painted teeth in Dawn of the Gods is another complete failure because Vila actually seems scared of it - if he'd treated it with the contempt it deserved, no problem.
Louise