Hey Nandini, I know you said YA, but I noticed that there are a couple of MG covers on your list, so I'll throw out a few of those:
MILLICENT MIN, GIRL GENIUS and STANFORD WONG FLUNKS BIG-TIME, Lisa Yee
THE SAVAGE FORTRESS, Sarwat Chadda
*cough* GEEKS, GIRLS, AND SECRET IDENTITIES, some random chump
And in the YA camp:
MY LIFE AS A RHOMBUS, Varian Johnson
WE WERE HERE, BALL DON'T LIE, and MEXICAN WHITEBOY by Matt de la Pena