If you like Diary of a Wimpy Kid, you might like:
Clueless McGee by Jeff Mack
Through a series of letters to his father, a private investigator, fifth-grader PJ "Clueless" McGee tells of his efforts to discover who stole macaroni and cheese from the school cafeteria.
Star Jumper: Journal of a Cardboard Genius by Frank Asch
Determined to get far away from his evil little brother, Alex works to design a spaceship that will take him so far away from Earth that not even the NASA experts can find him.
Ellie McDoodle by Ruth McNally Barshaw
Eleven-year-old Ellie McDoodle illustrates her sketchbook with chronicles of her adventures and mishaps while camping with her cousins, aunt, and uncle.
Attack of the Fluffy Bunnies by Andrea Beaty
At Camp Whatsitooya, twins Joules and Kevin and new friend Nelson face off against large, rabbit-like creatures from the Mallow Galaxy who thrive on sugar but are not above hypnotizing and eating human campers.
Dear Dumb Diary: Lets Pretend this Never Happened by Jim Benton
Entry in Jamie's diary: school was okay today. Angeline got her long hair tangled in one of the things she has dangling from her backpack, and the school nurse took a pair of scissors and snipped two feet of hair from the left side of her head.
Bad Kitty Gets a Bath but Nick Bruel
Takes a humorous look at the normal way cats bathe, why it is inappropriate for humans to bathe that way, and the challenges of trying to give a cat a real bath with soap and water.
How to Train Your Dragon by Cressida Cowell
Chronicles the adventures and misadventures of Hiccup Horrendous Haddock the Third as he tries to pass the important initiation test of his Viking clan, the Tribe of the Hairy Hooligans, by catching and training a dragon.
Charlie Joe Jackson's Guide to Not Reading by Tommy Greenwald
Middle schooler Charlie Joe is proud of his success at avoiding reading, but eventually his schemes go too far.
Stink and the Incredible Super-galactic Jawbreaker by Megan McDonald
Seven-year-old Stink Moody discovers that he can get free samples by writing letters to candy companies and plans a surprise for his best friend's birthday.
Big Nate: in a Class by Himself by Lincoln Peirce
Supremely confident middle school student Nate Wright manages make getting detention from every one of his teachers in the same day seem like an achievement.
Stuart’s Cape by Sara Pennypacker
Bored because there is nothing to do in the house to which his family has just moved, and worried about starting third grade in a new school, Stuart makes a magical cape out of his uncle's ties and has a series of adventures.
My Life as a Book by Janet Tashjian
Dubbed a "reluctant reader" by his teacher, twelve-year-old Derek spends summer vacation learning important lessons even though he does not complete his summer reading list.
Loser List series by Holly Kowitt
When Danny gets caught trying to cross his name off the "Geek" list in the girls' bathroom, he's sent to detention.