What cards do you consider worst (and why)?
(Worst generaly/for specific civ (i'm most interested in Dutch, Ports and Germans)).
I have only small experience with Dutch and with others almost none. So i'll name only one cathegory:
Plantation boost cards for Dutch. Why are they useless? Becose Dutch have around 2-3 plantation worth income from bank, so when it comes to mills+plantation economy, dutch have around 3-4 mills and 0-2 plantations (where others have something around 1:1 mills/plantations). Therefore 15% plantation boost for Dutch gives much less for them than for others.
And production boosting cards in general starts paying itself after geting around 6666 of food/gold from mill/plantation (before that 1000 f/g crate is better), so they can start paying itself in period where Dutch dont want to get (becose he is outproduced by anyone) and where game usualy dont get.