Thus, here goes the list. In approximate descending order (because I'd never be able to decide an exact order):
Anna Dressed in Blood. This one is my favourite. I love it, love it, love it. Grey and red are two of my favourite colours, and her hair's so pretty, and and...sigh. I dunno. I just love it.
Girl of Nightmares is also pretty high on my list. I liked Anna Dressed in Blood better though, as this one is less grey and the red is a bit too orangey.
Splendors and Glooms. Aaah, just look at that. So creepy and atmospheric. I love the giant hand appearing from underneath that beautifully red curtain. And then there's the back cover... But I won't spoil it for you.
The Humming Room is illustrated by my favourite cover illustrator and written by one of my favourite authors. What an awesome combination. I ended up not liking the book quite as much as Ellen Potter's other books (The Kneebone Boy and Pish Posh were really awesome), but Jason Chan's artwork was as lovely as always.