I have several items which bugged out from completed quests by not letting me to sell, use or drop them.
For instance, after you start "Night to remember" quest and woke up in the temple the priestess asks you to clean it with options for you of bribery or cleaning.
Basically, I bribed her and picked up a "Giant's toe" - now the quest is done, but I can't get rid of the giant toe. I found another toe somewhere, now I have two pieces of them just laying in inventory.
For those who haven't started the quest - that was one of the items from the "cleaning" activity you might got done instead of bribery (or any other option which I can't remind right now).
Another thing is the wine bottle, I don't remember how it gone through any quest I've encountered on the way, but any time I stack another bottle - I can't do anything about it, it just says that quest item can't be manipulated.
Now I have around 14 bottles of wine with a 0.5 weight which can not be transfered in any way.
There is another item in inventory, I forgot which one unfortunately, but again - it is not connected to any active quest.
