I was a tad disappointed that I couldn't find more inaccuracies in the new film, so I've started re-reading the series. From the beginning. As one does. Then, instead of being inspired to complain, rant and whine, I was once again swept up in the fun story and reminded once again why I love the series.
Here are a few of my favourite quirks in the first novel, which I just finished re-reading:
The sherbet lemons
The letter addressed to the cupboard under the stairs
Fred and George promising to send Ginny a Hogwarts toilet seat after their mother "suggests" they blow up a lavatory
Every scene with Peeves, especially "Shan't say nothin' if you don't say please!" "Please?" "NOTHIN!"
Lee Jordan's Quidditch commentary
Neville and Ron fighting Malfoy, Crabbe and Goyle at the Quidditch game
Gred and Forge
Mars is bright tonight
Trying to remember how to make a forgetfulness potion
Fred and George sending Harry a toilet seat when he's in the hospital wing
The point is, I went for several years thinking I couldn't stand to re-read this book again as I've read it so many times. However, if you're in the same boat, give it a chance. You just might find some favourite little bits that make it worthwhile.