I think this is really two questions in one: which card do you hate (but often use yourself)... and which card do you hate (and never use yourself)
Hate but often use: dim shield, obviously.
(Dishonourable mentions: reverse time, otyguh, maxwell's demon)
Hate and never use: Dusk Mantle, Fog Shield: the text on the cards is obviously wrong!! Their block percentage is much higher than written! At the same time, they're far too unreliable to use in one's own deck!
(Dishonourable mentions for the exact same reason: skull shield, thorn carapace)