A few days ago a kid asked me for books "like" the Diary of a Wimpy Kid series by Jeff Kinney. I sighed, then set to work coming up with suggestions.
     Basically I tried to find titles that fit a few or all of the following criteria:

aimed at boys
first-person narrator
diary format
school stories

     Here's my list, which I'll be putting on an end-cap display:

The Absolutely True Diary of a Part-Time Indian by Sherman Alexie

Whales On Stilts! by M.T. Anderson

The Strange Case of Origami Yoda by Tom Angleberger

Science Fair by Dave Barry & Ridley Pearson

Superfudge by Judy Blume

NERDS by Michael Buckley

Notes From a Totally Lame Vampire by Tim Collins & Andrew Pinder

Joey Pigza Swallowed the Key by Jack Gantos

The Day My Butt Went Psycho by Andy Griffiths

Just Joking! by Andy Griffiths

Flush by Carl Hiaasen

Swindle by Gordon Korman

Leon and the Champion Chip by Allen Kurzweil

I Am a Genius of Unspeakable Evil and I Want To Be Your Class President by Josh Lieb

In the Land of the Lawn Weenies by David Lubar

My Rotten Life: Nathan Abercrombie, Accidental Zombie by David Lubar

Middle School, the Worst Years of My Life by James Patterson, Christopher Tebbetts, and Laura Park

Big Nate by Lincoln Peirce

Captain Underpants by Dav Pilkey

How To Eat Fried Worms by Thomas Rockwell

The Dork Diaries by Rachel Russell

Wayside School Gets a Little Stranger by Louis Sachar

Guys Read: Funny Business edited by Jon Scieszka

Guy Time by Sarah Weeks

Zorgamazoo by Robert Paul Weston

Malice by Chris Wooding

Stanford Wong Flunks Big-Time by Lisa Yee

Books by Roald Dahl, while not realistic, might be comedic & snarky enough to fit the bill.