So here they are, in semi-approximate order, favourite first:
Music, Language, and the Brain. I think this cover might actually be tied with Mr. Was, although the effect does not come through very well in the picture above. It's definitely better in person. Anyhow, the musical symbol swirly-ness and shimmery colours give hint of the immense complexity of language and music that is examined in this book.
Game. There's just something about blood that I really like on covers. It's something about the redness (usually if on a cover, contrasted strongly with another colour such as grey), and the fluidity. As an added bonus, the inside cover is all blood-splattered and lovely. I actually have it on my shelf without the dust jacket because I like the inside cover so much.
And speaking of bloody covers: Slice of Cherry. Oooo, just look at that--so creepy and pretty!
And for yet another one I like for its blood: Antigoddess. (I like blood, ok?) I don't think this one is quite as good as it could be, but I like it. It fits the story well.
Ender's World. Look, it's all spacey and pretty!
Seraphina. Pretty town, pretty dragon--pretty, pretty. There's a new version of this cover that is weirdly blue and green, and completely destroys the effect, I think. This one is the best.
The Princess Curse was illustrated by the awesome Jason Chan, who I consider my favourite cover illustrator (although that doesn't really say much, since he is the only cover illustrator I know by name). Any cover by him pretty much automatically makes a Top Ten (Or So) cover list. He also did The Humming Room (from last year's list) and The Kneebone Boy (which would make a list of my favourite covers ever, I think) and Winterling (which I also read this year, and so is listed below).
And because it is also illustrated by Jason Chan, here is Winterling:
Runners Up (in No Particular Order): the infinity sign and general swirly-ness of Breath, the humorous suitability of the two Pirates! books, the black background and white geese of Goose Chase, the importance of the letters on Lexicon, the colourfullness and promise of Ordinary Magic, the simplicity of the silhouette on The Spark, the colour scheme and suitability of Unbroken, and the character illustration of Stolen Magic.
P.S. See also my list from last year: Top Ten (Or So): Covers of Books Read in 2012.