Book that made me laugh out loud

For me, "The Rosie Project" definitely comes to mind here.  I loved the way that Don Tillman was in many ways "the straight man" because he was unaware that his behaviour was unconventional.  His observations about people's BMIs and his commitment to science at all costs were absolutely classic.  I'm hoping that Graeme Simison can once again hit one out of the park with his new book "The Rosie Effect".