I mostly agree with silverspawn's ranking, although I do have a few disagreements,
Chapter I: The Bad Cards
205. Masquerade
Masquerade is entry #2 in the previously mentioned list. For a while, I thought this card was actually worse than Possession, but it's absolutely not. Really, it's not even close. The only reason I ever thought so was that I had forgotten how bad Possession really is. I probably was lucky not to play with it for a while.
That said, I still hate it, and the reason for that is that pass mechanic is not designed to hurt your opponent, so when it does, it feels unjustified and unfair quite similar to possession. They are my cards. Not yours. *sigh*
In my experience, it is very rare that a good card is stolen with Masquerade. The cards I mostly see changing hands are copper/estate - and, later in the game, silver/$3 actions.
Does anyone have stats on how often a good card gets passed through Masquerade?
My feeling is that although Masquerade can be quite unfair, it's unfair so rarely that it doesn't belong to the list.
Chapter 2: The Weak Cards (And Outliers) - Part one
199. Adventurer
Adventurer is the same as Scout, really. It costs 6$, even though it could easily cost 3$, making it probably the second weakest card in the game. Digging for Treasure cards as a concept is okay, but again, that doesn't help if the card is too weak to ever get bought.
I know I'm in the clear minority here, but I believe Adventurer gets to really shine if not outright dominate on some boards - which should at least rank it above Duchess.
Adventurer is quite nice if you get to trash the copper early, if the other terminal actions on the board are weak, if Platinum is available, and if there are strong junkers.
Just think about - if you get to trash all the copper, each Adventurer is guaranteed to give at least $4. This means in the absence of good terminal actions, getting 1 Adventurer is strictly better than getting 1 gold. In Colony games you can easily get 6+ gold by playing an Adventurer, which is invaluable when you draw a hand full of provinces/curses/ruins.
Adventurer also has a nifty interaction with tunnel, and with cards that make you put your junk on top of your deck such a Pearl Diver.
I know adventurer is a terrible card nearly all the time, but in the few cases it is bought it can be devastating.
Plus, it is always nice to beat down someone with a card widely seen as utterly mediocre
.
Chapter 2: The Weak Cards (And Outliers) - Part two
192. Contraband
The idea behind Contraband is probably to make you gain unconventional cards, kind of like Swindler, rewarding your creativity, and causing you to have a different type of game. I can appreciate this intention, but like many cards on this list, it fails due to the fact that it's just too weak. For this one, I can't help thinking that an extra coin would solve everything. As is, it's just not a factor in most games. I find that, what Contraband needs in order to be viable (aside from multiple cheap engine components), is a way to remodel it into a better card, because it's just so weak in the end game. Upgrade is ideal here; play Contraband to build your engine, then upgrade it into a gold, and profit.
I find the Contraband +buy to be invaluable on boards without other +buy and many engine pieces to buy - in fact I'd much rather buy Contraband instead of, say, Woodcutter.
Moreover, if you play Contraband before your other treasures, the other person has no idea how much $ you really have, meaning they may often ban the wrong item. Even late game, you can often buy double Duchies if they ban Provinces.
I'm also surprised you didn't mention
Chancellor/
Feast/
Saboteur. Maybe in the next list?