dd is a voracious reader so i just checked her bookshelves-she realy like the books by meg cabot (she wrote 'princess diaries' but also has others like the 'airhead' series which dd has realy enjoyed).
i adored 'to kill a mockingbird' at that age.
'esperanza rising' by pam munoz ryan was very good (multiple award winner)-it's about a wealthy young girl in mexico whose life is shattered and she and her mother have to flee to the depression era labor camps of california.
'code talker' by joseph brughag is supposed to be great. it's about the navajo fluent marines who were used by the u.s. to send and receive coded messages during ww2.
dd LOVED 'of mice and men'-it got her to want to read other steinbeck books. she will still have it as a required book for english, but she figures having pre-read it will give her an advantage when the assignment comes up.
i enjoyed the 'anne of green gables' series at that age.
OMG- i just remembered, when i was in 7th grade the absolute MUST READ BOOK and it's still considered a must read (and reread and reread) by many kids that grade-'the outsiders' by s.e. hinton. it's a great read and the fact the author was 15 when she started it, 16 when it was published just makes it even more appealing to that age group.