Lemony Snicket and Anthony Horowitz are fabulous. If you have to do a very long car journey, get the Lemony Snicket audiotapes - they are fantastic, and really good for adults to listen to as well as the kids.
Again we listened to Skellig on audiotape and I thought it was stunningly good - had dd (then 6) and ds (then 10) enthralled all the way to Disneyland Paris. Haven't had any of his actual hard copy books yet, but I'd say he writes very well.
The David Almond books are fab and an absolute bargain on The Book People at the mo. Just ordered them for ds1 and also ordering them to use as class readers for yrs 7 and 8. Lemony Snickett rocks and the Alex Rider books are great. Buy them all but read them all yourself b4 giving to nephew!!!!