My son acquired these books over a series of birthdays and everyone in my family has read them at least once, so I thought I'd find out first-had what all the laughter was about.
I have to say, except for a few parts, I didn't think they were that funny.
First, I've seen the first movie and after I've seen a movie, the book sometimes just isn't that great. That held true, in this case.
I definitely read things from an adult's point of view, which, I believe, is why these books just weren't that funny to me. Mostly, they were a quick read, slightly entertaining, and one of them (the yellow one) was really obnoxious. Greg Heffley is obnoxious. He's so full of himself! It's no wonder Rowley doesn't want to be his friend! (hee hee) As I read these as a parent, I couldn't help thinking, "I sure hope my kids don't try this crap". I know, I need to lighten up, they're meant for the younger readers in my house, not for me. And my kids love them. When I said they've read them at least once, it's more like 3-5 times PER BOOK. They LOVE them. From an adult's point of view, though, I give them a "meh" with a simultaneous shoulder shrug. ;)
But, now I can say I've read them and I know what my family (husband, included) is talking about when they say things like, "Remember when Greg tried to use the force to elevate the remote control from the coffee table to his hand?" or "Wasn't it funny when the one kid played the tuba behind the curtain?".