My least favorite card is probably Doctor. (OK, I have six cards left in my deck: three Coppers, Estate and a Silver. So let's name Copper... ->> FUUUUUUUU!!! you know what happens)
But it has a nice use in a middle/late game sometimes, just for reordering, it's almost like a free Scout in your deck!!, very useful.
Btw, about Rebuild, is it just me or people nowadays play way less Rebuild mirrors than say a year ago?
Maybe we became more sophisticated at playing engines or maybe Rebuild was just a tiny bit overestimated initially.
Any opinions?