I preferred Asylum and City to what I've played of Origins so far. City was Asylum on a larger scale.
Origins is more of the same but has this detective element to it where you re-create a crime scene to get clues which I'm not a fan of. Other than that it has a lot of the side bits that can in the first two games.
ok, so i am definately skipping the origins. i liked the stealth and the confinement in the asylum, that did not work in the city for me. i got bored too quickly.
re-creating crime scene sounds tedious. if i want that, i will play the latest sherlock holmes game (which i did by the way, and it is awesome)
i hope knight will be perfect though... not sure why i expect that, but a man can dream.