I'm a librarian who loves anime, manga, and reading a wide variety of genres.
Right now, most of the best sales are focused on the used and clearance books. I found a few I was interested in, but the section with the best discounts turned out to be the manga and graphic novels area, where both new and used volumes had the current maximum discount.
Here are a few of the things I bought:
FukuFuku: Kitten Tales (Chi's Sweet Home) - Konami Kanata - This is by the same person who created Chi's Sweet Home. Flipping through it, a few differences are apparent: readers don't get a peek into the cat's thoughts, the owner is an older woman rather than a family, and everything is in black-and-white.
The Heiress and the Chauffeur, Vol. 1 - Keiko Ishihara - It doesn't look like anything particularly special or original, and I'm sure I'll be donating it to my library eventually, but it was on my "want to read" list.
Honey So Sweet, Vol. 1 - Amu Meguro - I've heard mixed things about this series, but it's supposed to be pretty sweet.
Azumanga Daioh Omnibus - Kiyohiko Azuma,Stephen Paul - I've read this before and remember enjoying it.
Wolf Children: Ame and Yuki - Yuu,Mamoru Hosoda - I doubt I'd have bought this under other circumstances - my hardcover manga buying is limited almost entirely to Kaoru Mori's works. Anyway, I own the movie too, but haven't watched it yet.
Of the Red, the Light, and the Ayakashi, Vol. 1 - HaccaWorks* - The cover makes me think of a bunch of other series, but I've wanted to at least try it for a while. If it doesn't work out, then my library's manga collection will grow a little more.
And now for some of the novels, most of which started off really cheap and then became pathetically cheap with the additional discount:
The Science of Attack on Titan - Rikao Yanagita,Hajime Isayama - This was counted as manga, although it's actually a nonfiction examination of the science behind Attack on Titan. It answers questions like "If a Titan comes running, how fast do you have to go in order to get away?", "How could Titans be destroyed as a species?", "Would it really be possible for one Titan to rip through another with a single punch?" and more.
Surface Detail - Iain M. Banks - Do you know how often I've tried to find a Culture novel, any Culture novel, at this store? Pretty much every time I visited. Now I've finally found one there, and it's even one I don't already own.
The Concubine's Tattoo - Laura Joh Rowland - I'm almost certain I've read one of the books in this series before. I just can't remember whether I liked it or not.
Ring - Koji Suzuki,Robert B. Rohmer,Glynne Walley - I've read this already, but it was years ago. I figured that, since I was getting its sequel, Spiral, I might as well buy it too so I could reread it.