Trolls vs. Cowboys in the Arctic: (Mega Mash-up)Featured
My twelve year old son loves the Mega Mash-up books. They're a hybrid of comic book/cartoons and chapter book. I love that beneath the silly adventures there's a strong theme of the importance of being resourceful and of working with others as a team.
If you have any boys who are reluctant readers, this might be the series to turn them onto books.